What if deku became spongebobs sidekick

 The rain in Musutafu fell in sheets, slicking the pavement of the narrow alleyway and reflecting the neon glow of the main street just a few blocks away. For Izuku Midoriya, known to the world as the hero-in-training Deku, the rain was just another variable to calculate. 

Water meant less friction on the soles of his iron-soled boots. It meant decreased visibility. It meant civilian umbrellas blocking sightlines. 

Izuku crouched on the rusted fire escape of a four-story apartment complex, his emerald eyes scanning the shadows below. His breath plumed in the chill night air, his mind racing through a dozen different tactical scenarios. The emerald lightning of One For All danced faintly across his skin, a steady hum of power held tightly in check at eight percent. He couldn't afford to let his guard down. The villain he was tracking tonight wasn't a powerhouse like Muscular, nor a mastermind like Shigaraki, but in the world of Quirks, unpredictability was often deadlier than raw strength. 

The police dispatch had identified the suspect as a low-level smuggler known as "Rift." His Quirk, according to the files Izuku had meticulously memorized, allowed him to tear temporary, unstable holes in the fabric of space. 

A trashcan clattered in the alleyway. 

Izuku’s head snapped toward the sound. Down in the gloom, a figure cloaked in a heavy, water-logged trench coat was frantically attempting to pry open the grating of a storm drain. He had a stolen lockbox tucked under one arm. 

Target sighted, Izuku thought, his analytical mind immediately breaking down the geometry of the drop. Distance: roughly forty feet. Obstacles: none, besides the rain. If I drop down using Full Cowling at ten percent, I can intercept him before he opens another rift. I have to aim for a non-lethal submission, pinning his arms to prevent his Quirk activation.

"Stop right there!" Izuku called out, his voice cutting through the drumming rain. 

The figure froze, his head jerking up. Beneath the brim of a sodden fedora, a pair of panicked, wide eyes locked onto the green-clad hero above. 

"Deku!" the smuggler hissed, recognizing the iconic bunny-eared cowl that hung around Izuku's neck. "Stay back! I'm not going back to Tartarus!"

"You're cornered, Rift," Izuku said, leaping from the fire escape. He fell gracefully, the green lightning surging around him as he activated One For All: Full Cowling. He landed with a heavy splash in a puddle just ten yards from the villain, the impact absorbing seamlessly into his knees. "Drop the stolen property and put your hands behind your head."

Rift didn't comply. Instead, panic contorted his features. He dropped the lockbox, raising both his hands. His palms began to glow with a sickening, pulsating magenta light. The air around his hands warped and shimmered like heat rising from summer asphalt, accompanied by a sound like tearing canvas. 

"I said stay back!" Rift screamed. He thrust his hands forward. 

A tear in reality ripped open in the middle of the alleyway. It wasn't a clean portal like the ones Kurogiri created. It was jagged, unstable, and violent. The edges of the rift sparked with chaotic energy, pulling at the rain, the loose garbage, and the very air itself like a localized black hole. 

Izuku braced himself, digging his iron soles into the asphalt to resist the sudden, terrifying suction. The wind howled, pulling at his costume. His control over the Quirk is slipping, Izuku realized with growing horror. The rift is too big. It's unstable. If he doesn't close it, it might collapse and take half this city block with it!

"Close it!" Izuku shouted over the roaring wind. "You're going to lose control!"

"I... I can't!" Rift wailed, digging his own heels in as he was slowly dragged toward his own creation. The magenta light flared blindingly bright. 

Izuku didn't hesitate. Heroism wasn't just about fighting villains; it was about saving lives, even the lives of the villains themselves. Pushing One For All to fifteen percent, Izuku launched himself forward, fighting against the immense gravitational pull of the dimensional tear. 

"Detroit..." Izuku muttered, pulling his arm back, intending to use the air pressure of a smash to blow the villain out of the portal's trajectory and disrupt the energy field. "...Smash!"

He threw the punch at the ground in front of Rift. The shockwave shattered the asphalt, launching the villain backward, away from the yawning magenta maw. But in doing so, Izuku sacrificed his own footing. 

The recoil of the smash, combined with the intense vacuum of the portal, proved too much. Izuku’s boots lost purchase on the slick, broken ground. Time seemed to slow down. He saw Rift tumble safely out of range, gasping for breath on the wet pavement. But Izuku’s own momentum carried him forward, straight into the chaotic, swirling center of the rift. 

No, Izuku thought, his eyes widening as the magenta light consumed his vision. 

The last thing he heard before the world dissolved was the sound of reality snapping shut behind him. 

Sensory deprivation was a terrifying thing. 

For what felt like an eternity, Izuku existed in a state of absolute nothingness. There was no up, no down, no sound, and no light. It was as if his very consciousness had been suspended in a vacuum. His heart hammered in his chest, a frantic drumbeat that was the only proof he still existed. 

Then, the nothingness shattered. 

It was replaced by a chaotic kaleidoscope of colors and sounds. Izuku was tumbling, thrown like a ragdoll through a tunnel of swirling neon lights. Strange shapes flashed past him—things that looked like floating clocks, distorted buildings, and bizarre geometric patterns that hurt his eyes to look at. The physical toll was immense. It felt as though his body was being stretched and compressed simultaneously. He squeezed his eyes shut, trying to activate One For All to stabilize himself, but the energy wouldn't answer his call. It was as if this strange dimension was suppressing his Quirk. 

Think, Izuku, think! he told himself, trying to suppress his rising panic. Rift's Quirk operates on spatial distortion. If this is a wormhole, there has to be an exit point. I just need to brace myself for the impact.

Suddenly, the swirling lights vanished. 

Gravity returned with a vengeance. Izuku felt himself falling. The air around him was freezing cold. He opened his eyes, trying to orient himself to prepare a landing roll, but he couldn't see the ground. In fact, he couldn't see much of anything. Everything was tinted in a murky, deep blue. 

Before he could process this, he hit the surface. 

SMACK.

The impact knocked the breath out of his lungs. But he didn't hit concrete, or dirt, or a rooftop. He was entirely submerged. The freezing shock of the environment engulfed him instantly. 

Water. He was in water. 

Izuku thrashed, his eyes burning as he forced them open. He was surrounded by a vast, seemingly endless expanse of blue. Bubbles rushed past his face as he sank. Instinctively, he opened his mouth to gasp for air, but a torrent of salty, briny water rushed into his throat. He choked, violently coughing underwater, which only expelled what little precious oxygen he had left in his lungs. 

Panic, pure and primal, seized him. He kicked his legs, trying to swim upward, but the heavy iron soles of his costume boots were like lead weights dragging him down. The pressure around him was immense, pressing against his eardrums and his chest. 

Where am I? his mind screamed, his vision beginning to blur at the edges. An ocean? A lake? How far did that portal send me? 

He frantically reached down, trying to unbuckle his heavy boots, but his fingers were clumsy, his strength fading fast. The darkness of the deep was encroaching. His lungs burned with an agony so intense it eclipsed any broken bone he had ever suffered. 

He was drowning. Midoriya Izuku, the inheritor of One For All, was going to die drowning in an unknown sea. 

As his movements grew sluggish and his eyes began to close, a streak of bright, obnoxious yellow shot through the blue water above him. 

Izuku’s fading consciousness barely registered it. It looked like a rectangular sponge. But that made no sense. Sponges didn't move like that. Sponges didn't have limbs. 

Through the distortion of the water and his own dying vision, Izuku saw a pair of large, bulbous white eyes with bright blue irises staring down at him. A pair of spindly, yellow arms reached out. 

I'm hallucinating, Izuku thought, his brain shutting down. I'm hallucinating a cartoon character in my final moments...

The yellow blur grabbed the collar of his hero costume. With surprising strength, the creature jerked Izuku upward. But it was too late. The darkness closed in completely, and Izuku Midoriya slipped into unconsciousness. 

"Is he dead? SpongeBob, did you bring a dead guy into my Treedome?"

"He's not dead, Sandy! Look, his chest is moving! He's just... waterlogged. I think."

"Well, he's definitely not from around here. Look at his clothes! He looks like some kind of weird, green action figure. And what's with the red shoes? Are those metal?"

"Maybe he's a robot? Patrick, do you think he's a robot?"

"I don't know, SpongeBob. Let's poke him with a stick!"

"Patrick, no! Don't poke the mysterious surface-dweller with a stick!"

The voices filtered through the thick fog of Izuku's mind. They were strange voices. One was a deep, gravelly tone, sounding remarkably dim-witted. Another was a southern, feminine drawl. The third was high-pitched, nasal, and vibrated with an exhausting amount of energy. 

Izuku groaned, his eyelids fluttering. His throat felt raw, and there was a lingering taste of intense salt and seaweed in his mouth. He drew in a breath, and to his immense relief, his lungs filled with sweet, dry oxygen. 

He cracked his eyes open. The light above him was blindingly bright, like an artificial sun. He blinked a few times to clear his blurry vision, trying to piece together his surroundings. He was lying on a patch of soft, green grass. That was a good sign. Grass meant land. Land meant he wasn't drowning anymore. 

Slowly, the blurred shapes standing over him came into focus. 

Izuku froze. His breath hitched in his throat. His analytical mind, which had never failed to process the most bizarre Quirks and situations, came to a screeching, grinding halt. 

Standing to his left was a squirrel. A perfectly normal-looking squirrel, except it was roughly the size of a human toddler, and it was wearing a full, pressurized astronaut suit with a glass dome helmet. 

Standing to his right was a starfish. It was large, pink, and incredibly rotund. It was wearing lime green swimming trunks adorned with purple flowers. It was currently holding a large stick, looking profoundly disappointed that it wasn't allowed to use it. 

And standing directly over him, wringing its spindly hands together, was a bright yellow, rectangular sea sponge. It was wearing a crisp white collared shirt, a red tie, brown square pants, and shiny black shoes. It had large buck teeth, a long nose, and enormous, expressive eyes that were currently filled with worry. 

"Oh, Neptune be praised!" the sponge squeaked, throwing his hands up in the air. "He's awake! Sandy, he's awake!"

Izuku scrambled backward, his instincts kicking in. He pushed himself into a crouch, his back pressing against the trunk of a massive oak tree. He raised his arms in a defensive guard, his eyes darting frantically between the three impossible creatures. 

"Wh-who are you?!" Izuku stammered, his voice cracking. He looked around. They were inside a massive glass dome. Outside the glass, all he could see was blue water and schools of fish swimming lazily past. I'm underwater. But I'm in a dome filled with air. And there's a tree. And a squirrel. "What is this place? Is this a villain's lair? Are you Nomus? Mutants? What are your Quirks?!"

The three creatures blinked at him. 

"Quirks?" the starfish asked, scratching its pointy head. "Is that a type of mayonnaise?"

"No, Patrick, I think it's a type of music," the sponge whispered loudly. 

The squirrel in the spacesuit stepped forward, placing her hands on her hips. "Now hold on just a darn minute, partner. You're the one who fell out of a glowing purple sky-hole into our ocean, nearly drowned to death, and had to be hauled in here by SpongeBob. So how about you lower your fists before I have to introduce you to a Texas-style roundhouse kick?"

Izuku blinked. She had a Texas accent. A squirrel with a Texas accent in an underwater dome. 

"I... I..." Izuku lowered his arms slowly, the absurdity of the situation overriding his combat training. He pressed his hands to his temples, his breathing turning shallow. "Okay. Okay, Izuku. Think rationally. This is a Quirk. It has to be a Quirk. An illusion Quirk. Or maybe a hallucinogenic gas. Yes. Rift’s portal didn't teleport me; it exposed me to a neurotoxin. I'm lying in that alleyway right now, hallucinating."

"He's mutterin' to himself," the squirrel noted, raising an eyebrow. 

"Maybe his brain is broken," Patrick suggested helpfully. "We should try unplugging him and plugging him back in."

"I am not a machine!" Izuku blurted out, a bit louder than he intended. He took a deep breath, forcing himself to calm down. All Might always said a hero must keep their composure, no matter how bizarre the situation. He looked down at himself. His hero costume was soaked through, but otherwise intact. He reached up to touch his neck and felt a strange, rubbery patch stuck to his skin right over his windpipe. 

He tried to peel it off. 

"I wouldn't do that if I were you, buddy," the squirrel warned. "That there's a patented Sandy Cheeks Gilly-Patch. It taps right into your trachea and oxygenates your bloodstream, letting you breathe underwater like a fish. Took it off now, you'd probably start suffocating again if you stepped outside my Treedome."

Izuku paused, his fingers hovering over the patch. He looked at the squirrel. "You... you invented this?"

"Darn tootin'!" she said proudly, tapping her glass helmet. "Name's Sandy Cheeks. Scientist, inventor, and martial arts master from the great state of Texas. And you're currently sittin' in my Treedome, the only pocket of breathable air in all of Bikini Bottom."

"Bikini Bottom?" Izuku repeated, the name sounding completely ridiculous on his tongue. 

"Yep!" The yellow sponge bounced forward, extending a hand that felt oddly like a damp dish scrubber. "And I'm SpongeBob! SpongeBob SquarePants! I'm the one who found you sinking near Jellyfish Fields. And this here is my best friend, Patrick Star!"

"Hi," Patrick said, waving lazily. 

Izuku stared at SpongeBob's extended hand. He slowly reached out and shook it. It was incredibly soft, yet held a bizarre, spongy firmness. 

Okay, Izuku thought, his analytical brain forcibly booting itself back up. Let's assume, for the sake of survival, that this is real. I have been teleported to an underwater city called Bikini Bottom. The inhabitants are sentient, anthropomorphic sea life. 

Izuku’s hand drifted instinctively to the utility pouch on his belt. With trembling fingers, he unclasped it and pulled out his prized possession: Hero Analysis for the Future, Vol. 22. The notebook was specially designed by the Support Course to be completely waterproof and fireproof. He pulled a pen from his wrist gauntlet. 

"Fascinating," Izuku muttered, his eyes narrowing as he stared intensely at SpongeBob. The familiar, rapid-fire muttering that always accompanied his note-taking began to spill out of him. "A sentient Porifera. The biological implications are astounding. Sea sponges lack a central nervous system, digestive system, or circulatory system, yet this specimen exhibits high-level cognitive function, speech, and bipedal locomotion. Is it a mutation? A localized evolutionary leap caused by environmental factors? Furthermore, the cellular structure must be incredibly resilient. If he possesses the standard properties of a sponge, he could theoretically absorb massive amounts of physical trauma by displacing the kinetic energy through his porous body. A built-in shock absorption Quirk! And the starfish—Echinodermata. Starfish regenerate lost limbs. If he possesses sentience, does his regeneration apply to brain tissue as well?"

SpongeBob, Sandy, and Patrick stared at him in stunned silence as a literal wall of rapid-fire Japanese-accented gibberish washed over them. 

"Uh... Sandy?" SpongeBob whispered, leaning away from the fiercely scribbling green boy. "What is he doing?"

"I think he's calculatin'," Sandy said, looking impressed. "He talks faster than a rattlesnake on a hot tin roof."

Izuku snapped his notebook shut, his face flushed. "I-I'm sorry! It's a habit. I tend to overanalyze things. M-my name is Izuku Midoriya. My hero name is Deku. I'm a... well, I'm a hero-in-training from U.A. High School in Japan. On the surface. On Earth."

"Japan?" SpongeBob gasped, his eyes going wide. He pulled a sailor's cap out of nowhere, slapped it on his head, and struck a pose. "I know Japan! Land of the rising sun! Sushi! Karate!" He immediately began chopping the air with his hands, making high-pitched squealing noises. "Waa-TAH! Waa-CHAA!"

"SpongeBob, behave," Sandy chided. She looked at Izuku with a critical eye. "So, you're a human, huh? Never seen a human down here who wasn't wearing a bulky diving suit or riding in a submarine. And you said you're a 'hero'? Like, the folks in comic books?"

Izuku nodded, standing up slowly. His legs felt a bit wobbly, but he was recovering. "Yes. Where I come from, almost eighty percent of the population has a superhuman ability called a Quirk. Because of this, being a Superhero became an actual, government-sanctioned profession. We fight villains, stop disasters, and protect people."

SpongeBob froze mid-karate chop. 

His eyes slowly widened until they took up nearly half his face. His pupils dilated. A high-pitched, vibrating sound began to emanate from his porous body, like a tea kettle about to boil over. 

"A... a real..." SpongeBob vibrated violently. "A REAL SUPERHERO?!"

Before Izuku could react, SpongeBob vanished in a blur of yellow. A microsecond later, the sponge reappeared inches from Izuku's face, his eyes sparkling with unshed tears of pure joy. 

"By the rings of Saturn," SpongeBob whispered reverently, tracing a finger over the reinforced plating of Izuku's chest piece. "You're real. You're actually real. Just like Mermaid Man and Barnacle Boy!"

"Mermaid Man and Barnacle Boy?" Izuku echoed, tilting his head. The names sounded incredibly cheesy, even by Silver Age comic book standards. "Are they... heroes here?"

"Are they heroes?!" SpongeBob shouted, grabbing Izuku by the shoulders and shaking him excitedly. "They are the greatest heroes of the deep! Champions of justice! Protectors of Bikini Bottom! They use the power of the water to thwart evil-doers like Man-Ray and the Dirty Bubble! Oh, this is the greatest day of my life! Wait right here!"

SpongeBob reached into his pocket—a pocket that seemed physically impossible given the tight fit of his square pants—and pulled out a massive, heavily worn binder. He flipped it open, revealing pages upon pages of trading cards. 

"This is my Mermaid Man and Barnacle Boy trading card collection," SpongeBob said, his voice dropping to a serious, hushed tone. "I have all of them. Even the rare holographic 'Mermaid Man Buys Groceries' card. See?"

Izuku looked at the cards. The heroes depicted on them looked... old. Incredibly old. One was a human in a clamshell bra and green tights, wearing a starfish on his nose. The other was a skinny, grumpy-looking man with a sailor hat and a massive barnacle-covered nose. 

Despite the bizarre appearance of the underwater heroes, a spark of deep, profound recognition ignited within Izuku's chest. He looked at SpongeBob's shining, reverent eyes, and in them, he saw a mirror of himself at four years old, clutching his All Might action figure in front of his computer screen. 

This sponge was a fanboy. Just like him. 

A wide, genuine smile broke across Izuku's face. All the fear and anxiety of being trapped in another dimension melted away, replaced by the universal language of hero worship. 

"That's incredible," Izuku said, his tone matching SpongeBob's reverence. He reached into his own utility pouch and pulled out a small, slightly dented All Might keychain. "I have a collection too. Back home. Thousands of items dedicated to the greatest hero of my world: All Might."

SpongeBob gasped, staring at the muscular, smiling figure on the keychain. "He looks so strong! And his smile... it's like a beacon of justice!"

"Exactly!" Izuku beamed. "He always saves people with a smile. He's my idol. He’s the reason I became a hero."

"Mermaid Man is the reason I wake up every morning!" SpongeBob cried, grabbing Izuku's hands. "Oh, Deku, we have so much to talk about! We can discuss costume designs, secret bases, catchphrases—"

"Alright, break it up, you two nerds," Sandy interrupted, chuckling as she walked over. She tossed a dry towel to Izuku. "Dry yourself off, kid. Now, we got a bit of a problem. You say you fell through a portal?"

Izuku caught the towel and began drying his green hair. "Yes. A villain with a spatial distortion Quirk lost control. I fell in. I need to get back to Musutafu as soon as possible. My mentors and friends are probably worried sick, and that villain is still at large."

Sandy rubbed her chin, her bushy tail twitching. "Well, spatial distortion ain't exactly my usual field of study—I'm more of a mechanical and biological engineer—but I reckon if you got in here, I can build a machine to get you out. I'll need to analyze the residual dimensional energy on your clothes to lock onto your universe's frequency."

"You can do that?" Izuku asked, his eyes widening with hope. "How long will it take?"

"Given the complexity of interdimensional physics, and the fact that I have to build the quantum-tunneling resonator from spare submarine parts and acorn shells..." Sandy calculated, tapping her foot. "I'd say about three to four days."

"Four days," Izuku muttered. It was a long time to be missing, but it was far better than being stuck here forever. "Okay. I can manage that. Thank you, Sandy. I owe you my life." He bowed deeply, a perfect ninety-degree angle. 

Sandy laughed, waving him off. "Ah, don't mention it. Any friend of science is a friend of mine. You can crash here in the Treedome while I work. The air is good, and I got plenty of nuts and apples."

"Excuse me, Sandy," SpongeBob interrupted, raising his hand politely. "But I have a better idea! Deku is a real-life superhero! And right now, Bikini Bottom is completely vulnerable!"

"Vulnerable?" Izuku asked, his hero instincts flaring up. "Is there a villain attacking?"

"Well, no, not right now," SpongeBob admitted. "But Mermaid Man and Barnacle Boy are out of town! They went to the Annual Shuffleboard Tournament in Bass Vegas for the week! The Invisible Boatmobile is locked in the Mermalair, and the streets of Bikini Bottom are without a protector!" 

SpongeBob grabbed Izuku's arm, looking up at him with pleading, watery eyes. 

"Deku, while you're waiting to go home, you can't just sit in this dome! You have to come with me! We can patrol the streets! We can stop jaywalkers! We can rescue kittens from tall kelp stalks! Oh, please, Deku! Let me be your sidekick! We'll be the greatest crime-fighting duo since... well, since Mermaid Man and Barnacle Boy!"

Izuku looked at the sponge. He thought about the rigorous training at U.A., the life-or-death battles he had fought, the heavy burden of One For All. Patrolling an underwater cartoon city with a talking sponge sounded completely absurd. 

But then he remembered All Might's words. A hero's cape is meant to wrap up those who are suffering in terrible pain. 

And right now, this sponge was in terrible pain at the thought of his city being unprotected. 

Izuku couldn't help it. He smiled. "Well, SpongeBob... a hero's work is never done. I suppose I could help you keep an eye on things while I wait."

"EEEEEEEEEEEEEEEEE!" SpongeBob shrieked, a sound so high-pitched it vibrated the glass of the Treedome. He leaped into the air, doing a mid-air backflip. "I'M A SIDEKICK! I'M A REAL SIDEKICK! Patrick, did you hear that?!"

"I heard it," Patrick said, currently trying to eat an acorn whole. "Are you gonna get a cape? I want a cape."

"We have to go prepare!" SpongeBob yelled, grabbing Izuku by the hand and practically dragging him toward the airlock of the Treedome. "I need to show you the city! We need a secret handshake! We need to come up with a team name!"

"W-wait! My notebook!" Izuku stumbled, grabbing his notebook from the grass as SpongeBob pulled him along. 

Sandy watched them go, shaking her head with a fond smile. "That boy don't know what he just signed up for."

While Izuku Midoriya was making his first, bizarre friend in the underwater city, a far more sinister meeting was taking place on the other side of Bikini Bottom. 

The villain known as Rift had not escaped the alleyway unscathed. When Izuku's Detroit Smash had disrupted the portal's energy field, the resulting shockwave had shattered the dimensional tunnel as Rift tried to scramble away. He had been sucked into a secondary, smaller tear in reality. 

He didn't land in the soft, welcoming waters of Jellyfish Fields. 

Rift fell through the ceiling of a dark, incredibly depressing metal structure. He landed hard on a cold steel floor, groaning in pain as his bruised ribs protested. 

He lay there for a moment, waiting for the pro-heroes to slap cuffs on him. But the only sound was the hum of cheap fluorescent lights and the rhythmic dripping of something foul-smelling. 

Rift sat up, clutching his chest. He looked around. The room was sterile, circular, and made entirely of riveted iron. Double swinging doors led out to what looked like a dining area, though the tables were empty and covered in a thick layer of dust. The most overwhelming sensation, however, was the smell. It was a putrid, stomach-churning stench of rotting fish, old grease, and despair. 

"What... what is this place?" Rift coughed, gagging on the smell. "Is this a prison?"

"Worse," a tiny, booming voice echoed through the room. "It's a failing business."

Rift scrambled backward, his hands glowing with a weak, defensive magenta light. "Who's there?! Show yourself!"

"Down here, you oversized, land-dwelling ape."

Rift looked down. Standing on a metal worktable a few feet away was a creature so small Rift had to squint to see it properly. It was a single-celled organism, green, oval-shaped, with one massive yellow eye and two thin antennae. 

"Are you... a bug?" Rift asked, bewildered. 

The creature's eye twitched violently. 

"I am NOT a bug!" the creature bellowed, producing a tiny megaphone from behind his back to amplify his voice. "I am Sheldon J. Plankton! Criminal mastermind, evil genius, and rightful ruler of the Bikini Bottom fast-food industry! And you, you clumsy oaf, just put a hole in the roof of the Chum Bucket!"

Rift stared at the tiny green bean. "I... I don't understand. Where am I? Where's the sky? Why am I not drowning?"

"You're at the bottom of the ocean, genius," Plankton sneered, pacing back and forth on the table. "Though how you're breathing down here without a suit is beyond me. But frankly, I don't care. What I do care about is that glowing purple magic trick you just did with your hands. You just created a rift in space-time to get here, didn't you?"

Rift looked at his hands. His Quirk was weak from exhaustion, but it still functioned. "It's my Quirk. I can open portals."

Plankton stopped pacing. His single eye widened, a sinister, malicious gleam filling it. He dropped the megaphone. 

"Portals," Plankton whispered, his voice trembling with dark excitement. "Portals that can transport objects. Portals that can bypass walls. Portals that could, hypothetically, bypass the heavy steel vault doors of a certain crustacean-owned restaurant across the street?"

"I... I guess," Rift said, completely lost. "Look, I just want to get back to the surface. I need money. I had a whole lockbox of cash that I dropped when that brat Deku attacked me."

Plankton held up a tiny hand. "Hold on. You need money? My dear, confused giant... I have no interest in your surface currency. But..." Plankton smiled, revealing a row of sharp, menacing teeth. "...if you use your 'Quirk' to help me obtain a certain Secret Formula, I can promise you wealth beyond your wildest dreams. I have technology that can amplify your powers. We can pull anything you want from your world right into this room."

Rift hesitated. He was stranded, exhausted, and running from the law. This tiny creature was offering him a way out, and a way to power. 

"What kind of formula?" Rift asked. 

Plankton threw his head back and let out a high-pitched, maniacal laugh that echoed off the cold metal walls of the Chum Bucket. 

"The Krabby Patty Secret Formula!" Plankton cackled. "With your portals and my genius, Eugene Krabs won't know what hit him! We will rule Bikini Bottom! And then... the world!"

In the shadows of the Chum Bucket, an unholy alliance was forged. The quiet town of Bikini Bottom was about to face a threat unlike any it had ever seen, and only a quirkless sponge and a stranded hero stood in their way.

The transition from the dry, artificial atmosphere of Sandy Cheeks’ Treedome to the open waters of Bikini Bottom was, for Izuku Midoriya, an exercise in sheer sensory overload. 

Sandy had escorted them to the airlock, double-checking the Gilly-Patch adhering firmly to Izuku’s throat. "Now, remember," the Texan squirrel had warned, adjusting the dials on the heavy steel door, "that patch is doin' two things. It’s filtering the oxygen from the water straight into your bloodstream, and it’s regulating your internal pressure so you don't get squished like a ripe tomato under a boot. But it ain't magic. You're still underwater. The physics are gonna feel mighty different."

Izuku had nodded, mentally preparing himself. He took a deep breath of dry air as the inner door hissed shut, sealing him and SpongeBob in the small chamber. Water began to flood in from grates in the floor, rising rapidly past Izuku’s iron-soled boots, his kneepads, and his utility belt. 

He tensed, expecting the crushing weight and the freezing cold that had nearly killed him earlier. But as the water crested over his head, immersing him completely, the Gilly-Patch hummed with a faint, warm vibration against his skin. Izuku gasped out of instinct, and to his absolute shock, a cool, steady stream of oxygen filled his lungs. It didn't feel like breathing water; it felt like breathing slightly dense, humid air. Furthermore, the crushing hydrostatic pressure he had experienced during his initial fall was gone, neutralized by the patch’s localized forcefield. 

"See? Nothing to it!" SpongeBob’s voice echoed in the water, perfectly clear, though it carried a slight aquatic reverberation. The sponge was floating a few feet away, doing a relaxed backstroke. 

The outer door slid open, revealing the vibrant, bustling metropolis of Bikini Bottom. 

Izuku stepped out, his iron soles anchoring him firmly to the sandy seabed. His jaw dropped. It was one thing to hear about an underwater city; it was another entirely to behold it. 

Tall, colorful coral reefs had been hollowed out to serve as skyscrapers. Bizarre, muffler-shaped buildings dotted the landscape, connected by winding asphalt roads. Schools of anthropomorphic fish wearing business suits, dresses, and casual wear walked along the sidewalks or drove vehicles that looked remarkably like sunken boats with wheels. The sky above wasn't a sky at all, but a vast expanse of shifting oceanic blue, patterned with whimsical, five-petaled flower clouds floating lazily in the currents.

"It's... it's a completely functioning society," Izuku muttered, his eyes wide as he watched a green fish in a bowler hat wait patiently at a stoplight. "The infrastructure, the traffic laws, the architecture... it perfectly mimics terrestrial urban centers, but adapted for a subaquatic environment. How did this evolve? Is this a pocket dimension? A mutant enclave hidden in the Marianas Trench?"

"Welcome to Bikini Bottom, Deku!" SpongeBob cheered, grabbing Izuku's hand and pulling him along the sidewalk. "Come on! If we're gonna be a crime-fighting duo, we need to get you properly inducted! First stop, my house!"

Walking underwater was a bizarre sensation for the young hero. Despite his heavy boots keeping him grounded, every movement felt sluggish, met with the liquid resistance of the ocean. He tried to take a quick step and found himself practically gliding forward, his momentum carrying him further than intended. 

Water resistance is roughly 784 times greater than air resistance, Izuku calculated, observing SpongeBob, who seemed completely unhindered by the environment, skipping merrily along. I'll have to adjust my entire fighting style. If I use One For All to throw a punch, the kinetic energy will be drastically dampened by the water. Worse, the force of the strike will create a massive cavitation bubble and a shockwave that could cause indiscriminate collateral damage to civilian structures. I have to be incredibly precise.

They turned a corner onto a quiet residential street known as Conch Street. Sitting next to a large, Easter Island head made of stone was a massive, hollowed-out pineapple. 

"Here we are! Home sweet home!" SpongeBob announced, opening the heavy wooden door of the pineapple. 

Izuku stepped inside, his analytical mind once again blown away. The interior was fully furnished. A television made from a diver's helmet sat in the corner. A couch shaped like a lifesaver ring rested on a bamboo rug. There was a diving board leading up to a second floor. Everything felt absurdly cozy, defying every law of moisture and rot. 

"Meow."

Izuku looked down. A small pink snail with a blue shell was slithering across the floor, leaving a trail of slime. The snail looked up at Izuku with large, bored eyes. 

"Meow," it said again. 

"Ah, Gary! I'm glad you're awake!" SpongeBob bent down and patted the snail's shell. "Gary, this is Deku. He's a real superhero from the surface world! Deku, this is Gary, my pet snail."

"A... feline-vocalizing gastropod?" Izuku muttered, reaching into his pouch and producing his waterproof notebook. He immediately began sketching Gary. "Fascinating. The vocal cords of terrestrial felines have seemingly manifested in a marine invertebrate. Is this a Quirk, or just local biology? Hello, Gary. It's a pleasure to meet you."

Gary stared at Izuku, blinked slowly, and slithered away toward a bowl of food. "Meow."

"Don't mind him, he hasn't had his morning kelp-kibble," SpongeBob said dismissively. The sponge then stood up straight, his face adopting an expression of profound, comical seriousness. He marched over to a closet, threw open the doors, and rummaged through a pile of miscellaneous items. "Alright, Deku. If you're going to fill in for Barnacle Boy, we need to make this official. Every hero needs a moniker. A title that strikes fear into the hearts of evildoers and brings hope to the innocent!"

SpongeBob emerged from the closet. He had tied a purple towel around his neck like a cape and placed a metallic colander on his head. He struck a dramatic pose, hands on his hips, his chest puffed out. 

"I... am The Invincibubble!" SpongeBob declared, his voice echoing with a manufactured, booming resonance. "Able to blow bubbles in any shape! Able to clean up the foulest messes of injustice!" 

Izuku couldn't help but smile. Despite the comical appearance, SpongeBob’s sheer enthusiasm was infectious. It reminded Izuku of himself in his bedroom, wearing his mother’s homemade green jumpsuit, declaring himself a hero. 

"And you, my steadfast companion!" The Invincibubble pointed a yellow finger dramatically at Izuku. "You already have a hero name, but down here, to keep your surface-identity a secret, you need an aquatic alias! From this day forth, until Mermaid Man returns, you shall be known as... The Green Barnacle!"

Izuku blinked. The Green Barnacle. It wasn't exactly 'Deku,' and it certainly wasn't 'Lemillion' or 'Dynamight.' Barnacles were essentially parasitic crustaceans that stuck to rocks and boat hulls. But looking at the shining, reverent eyes of his new friend, Izuku wouldn't have dared reject it. 

"I am honored to accept the mantle, Invincibubble," Izuku said, bowing respectfully. 

"Huzzah!" SpongeBob cheered, tossing the colander aside. "Now, before we hit the streets to look for litterbugs and purse-snatchers, we must train! A sidekick must know the ways of the hero!"

"Actually, SpongeBob," Izuku interjected, flipping to a blank page in his notebook and clicking his pen. "Before we train, I need to understand your Quirk. Or... whatever you call your powers down here."

SpongeBob tilted his head. "My powers? You mean being a sponge?"

"Exactly," Izuku said, his eyes gleaming with the intense, almost manic curiosity that Uraraka and Iida knew all too well. "In my world, powers have limitations. They draw on physical stamina, require specific triggers, and adhere to certain laws of physics, even loosely. But watching you earlier... you defy almost every biological and physical law I know. If we're going to fight side-by-side, I need a complete tactical breakdown of your abilities."

Izuku sat down cross-legged on the bamboo floor. "Show me everything you can do. Hold nothing back."

SpongeBob grinned, his buck teeth shining. "Ooh! A talent show! Okay, Green Barnacle, watch this!"

What followed over the next thirty minutes was a display that completely dismantled Izuku Midoriya's understanding of reality. 

First, SpongeBob demonstrated his regenerative abilities. "Sometimes I get a little clumsy," he explained cheerfully. He grabbed his left arm with his right hand and, with a casual rip, tore his own arm completely off his body. 

Izuku screamed, dropping his pen. "SPONGEBOB! OH MY GOD! WE NEED A DOCTOR! WE NEED RECOVERY GIRL!"

"Relax, Deku, watch!" SpongeBob giggled. He held the severed, limp yellow arm in his remaining hand. A wet, popping sound emanated from his left shoulder, and instantly, a brand-new, perfectly functioning arm shot out of the socket. SpongeBob then nonchalantly tossed the severed arm over his shoulder, where it seemingly vanished into thin air. 

Izuku stared, his mouth hanging open. He slowly picked up his pen. 

"Super Regeneration," Izuku muttered, his hand flying across the waterproof paper. "Far surpassing the Nomu at the USJ. It's instantaneous. There's no visible exhaustion of cellular stamina. The subject does not register pain from dismemberment. This implies a nervous system that either doesn't transmit pain signals or immediately suppresses them."

"I can also do this!" SpongeBob announced. He took a deep breath, puffed out his cheeks, and suddenly, his entire body began to expand. His square shape morphed, stretching and twisting until he flawlessly took the shape of a massive, yellow acoustic guitar. He then strummed his own face, producing a perfect musical chord, before snapping back to his normal rectangular self. 

"Complete cellular manipulation and shape-shifting!" Izuku scribbled furiously, sweat beading on his forehead despite being underwater. "Similar to Edgeshot’s Foldabody, but without the mass limitations. He can alter his density, volume, and structure at will to perfectly mimic inanimate objects!"

"Oh, and I'm really absorbent!" SpongeBob added. He waddled over to a massive, hundred-gallon fish tank sitting in the corner of the room. He unhinged his jaw to a terrifying degree, placed his mouth over the tank, and inhaled. In one second, the entire hundred gallons of water vanished into SpongeBob. The sponge swelled to the size of a small car, his pores bursting with water. 

Izuku's pen snapped in half. He didn't even notice, pulling a spare from his belt. 

"Total mass absorption," Izuku whispered, his eyes wide with a mixture of terror and absolute awe. "Like Fat Gum, but with liquids. He could theoretically absorb an entire tsunami. He could neutralize water-based attacks completely." 

Izuku looked up from his notes, staring at the cheerful, squishy yellow cube that was currently wringing himself out over a potted kelp plant like a wet washcloth. 

Izuku’s mind raced. If SpongeBob was transported to my world and registered as a Pro Hero, his Quirk—let's classify it provisionally as 'Toon Force'—would make him virtually unstoppable. He can't be bludgeoned, slashed, or drowned. He can regenerate from total dismemberment in a microsecond. He can alter his physical form to adapt to any situation. He is a god-tier entity. He could probably outlast All For One in a war of attrition simply by letting All For One punch him until the villain died of old age.

"So?" SpongeBob asked, shrinking back down to his normal size. "What do you think of my powers, Green Barnacle?"

"I think," Izuku said softly, looking at his wildly scribbled notes, "that you are one of the most terrifyingly powerful beings I have ever met. And I am incredibly glad you're on the side of justice."

SpongeBob blushed, kicking his shiny black shoe against the floorboards. "Aw, shucks, Deku. I just like making people smile! Anyway, enough showing off! It's time for phase one of your sidekick training! Agility and evasion!"

"Right," Izuku nodded, closing his notebook and standing up. He stretched his legs, feeling the green lightning of One For All prickle beneath his skin, eager to be used. "Where are we training? A combat simulator? A ruined cityscape?"

"Even better!" SpongeBob produced two bamboo sticks with pink, woven nets attached to the ends. He thrust one into Izuku's hands. "We're going to Jellyfish Fields!"

While Izuku was marveling at the biological impossibilities of a sea sponge, Sheldon J. Plankton was hard at work breaking the laws of both science and decency in the Chum Bucket. 

The tiny villain stood atop a massive control console, wearing a miniature welder’s mask. Sparks flew as his robotic wife, a sophisticated supercomputer named Karen attached to a wheeled monitor, assisted him with a pair of mechanical arms. 

"Hold the plasma-torch steady, Karen!" Plankton barked over the noise. "If this flux-capacitor overloads, we'll blow a hole straight through the Mariana Trench!"

"I am holding it steady, Sheldon," Karen's deadpan, robotic voice replied from her screen, which currently displayed an eye-rolling emoji. "Though I still don't understand why you need to build a doomsday device out of literal garbage. And who is the tall, depressed man sitting in the corner?"

Plankton flipped his mask up, gesturing grandly to the shadowed corner of the laboratory. There, chained to a massive generator by a series of glowing energy cuffs, sat the villain Rift. He looked exhausted, his trench coat still damp, his face pale. 

"He is our golden goose, Karen!" Plankton cackled, rubbing his microscopic hands together. "This bipedal bottom-feeder possesses a 'Quirk'—a biological anomaly from the surface world that allows him to rip holes in the fabric of space! With a few modifications to my Chum-Transmuter, I've managed to hook his biological energy into our power grid. We are essentially using his body as an organic battery to force his portals open!"

Plankton scurried over to a large lever on the console. "Behold!" 

He yanked the lever down. A massive surge of electricity flowed from the Chum Bucket's generators, traveling through thick copper cables and shocking Rift. The MHA villain screamed in pain as his hands involuntarily lit up with blinding magenta light. A tear in reality ripped open in the center of the laboratory floor, swirling with chaotic energy. 

"Now, Rift!" Plankton commanded, his voice amplified by a microphone. "Think of the most dangerous, highly classified villain armories in your world! Pull the weaponry through the rift!"

Rift, trembling and sweating, focused his mind on a black-market warehouse he had once smuggled goods for in Kamino Ward. The magenta portal flared. 

Suddenly, a deluge of surface-world junk poured through the rift, crashing onto the metal floor of the Chum Bucket. There were crates of discarded Support Gear, broken robotic sentries from U.A. entrance exams, canisters of illegal quirk-enhancing drugs, and shattered containment pods that once held low-tier Nomu experiments. 

"Yes! YES!" Plankton cheered, diving into the pile of highly illegal Japanese hero-tech like a child in a ball pit. He surfaced holding a cracked, metallic gauntlet meant to fire explosive rounds. "Do you see the engineering on this, Karen?! It's magnificent! It's destructive! It's... a little rusty, but I can work with it!"

"So," Karen said, her screen showing a loading bar. "You're going to use advanced surface-dweller weaponry to... what? Blast open the doors of the Krusty Krab?"

"Oh, Karen, my sweet, naive computer wife," Plankton sneered, dragging the gauntlet over to a massive, cylindrical vat in the center of the room. The vat was filled with bubbling, putrid, dark red sludge. It was Plankton’s infamous Chum—a vile mixture of biological waste, rotting fish parts, and sheer culinary failure. 

"Blasting the doors open is too simple," Plankton monologued, pacing in front of the bubbling vat. "Eugene Krabs is paranoid. He has defense measures. He has a sturdy safe. And he has that meddlesome sponge, who somehow manages to thwart me with his infuriating optimism."

Plankton looked up at the massive vat of Chum, then over to the pile of MHA villain tech. 

"No. We need something that can crush the sponge. Something that cannot be reasoned with. Something made of pure, unadulterated evil and... whatever this sludge is." Plankton gestured to Rift. "This human's world has creatures called 'Nomus.' Mindless, genetically engineered bio-weapons designed only to destroy. I pulled the blueprints from a stolen hard drive in that pile of junk."

Plankton pressed a button on a remote. A mechanical claw descended from the ceiling, scooping up handfuls of robotic sentry parts, broken hero gear, and a canister of Quirk-enhancing chemicals. The claw dropped them directly into the boiling vat of Chum. 

"I am going to combine my robotics, the surface-world technology, and the dense, foul biological mass of my Chum to create the ultimate enforcer!" Plankton screamed, throwing his head back in maniacal laughter. "I will create a monster so horrifying, so powerful, that Eugene Krabs will hand over the Secret Formula just to spare his own life!"

The vat began to bubble violently. The dark red sludge glowed with an eerie, sickly green light as the chemicals and the Chum mixed. A low, guttural growl echoed from within the tank, shaking the floorplates of the restaurant. 

"Rise, my beautiful abomination!" Plankton yelled. "Rise... the CHUM-NOMU!"

Jellyfish Fields was, in Izuku’s opinion, one of the most beautiful places he had ever seen, terrestrial or aquatic. 

Rolling hills of vibrant purple and pink coral stretched as far as the eye could see, gently swaying in the ocean currents. Towering stalks of green kelp acted as trees, filtering the sunlight from the surface into a dappled, golden glow. And everywhere, drifting lazily through the water, were the jellyfish. They were pink, translucent creatures, emitting a soft, rhythmic buzzing sound like tiny bees. 

"Behold, Green Barnacle!" SpongeBob whispered loudly, crouching behind a coral bush. He held his net at the ready. "The majestic Jellyfish in its natural habitat. To be a hero, one must master the art of Jellyfishing. It teaches patience, agility, and precision. Plus, they make great jelly for toast!"

Izuku crouched beside him, holding his own net awkwardly. He analyzed the creatures. "They resemble terrestrial Cnidarians, but their bioluminescence is different. They’re emitting an electrical hum. Are they dangerous?"

"Oh, absolutely!" SpongeBob nodded cheerfully. "If they sting you, it feels like a thousand tiny lightning bolts hitting you all at once! It’s agonizing! That’s why we have to be quick."

Electrical discharge, Izuku noted. Similar to Kaminari’s Electrification, though likely lower voltage. Still, in an aquatic environment, electricity is highly conductive. If I get stung, the shock could disrupt my nervous system and cause me to lose control of One For All.

"Watch and learn," SpongeBob said. He placed a pair of thick, horn-rimmed glasses on his face—"For serious Jellyfishing," he whispered—and leaped from the bushes. 

Izuku watched in awe. For all of SpongeBob’s goofy demeanor, his movements were impossibly fluid. He didn't swim; he danced. He twirled through the water, spinning his net with the dexterity of a martial arts master wielding a bo staff. He leaped off a rock, did a triple mid-air somersault, and gracefully scooped a jellyfish into his net with a soft bloop. 

"Ta-da!" SpongeBob cheered, letting the jellyfish go, which buzzed away happily. "Now you try, Green Barnacle!"

Izuku stood up, taking a deep breath. He gripped the wooden handle of the net. He needed to adapt his terrestrial fighting style to the water. 

One For All: Full Cowling - Five Percent, Izuku thought. 

Red veins flared across his skin, instantly followed by the crackle of emerald green lightning. The power surged through his muscles. The water around him instantly reacted, the electrical current from his Quirk causing the nearby kelp to stand on end. 

SpongeBob gasped, dropping his glasses. "Woah! You have built-in Christmas lights! That is SO cool!"

Izuku didn't answer. He locked his eyes on a small group of jellyfish drifting about thirty yards away. 

Push off with the right foot. Compensate for the water resistance by angling my body like a torpedo. Keep the net tucked tight to reduce drag. 

Izuku kicked off the seabed. The iron sole of his boot left a crater in the sand. He shot forward like a green missile, the water parting around him. It felt like sprinting through a vat of syrup, but One For All powered him through it. In a blur of motion, he swung the net, aiming perfectly to scoop up three jellyfish at once. 

But Izuku had forgotten one crucial variable: the wake. 

His incredible speed, combined with the mass of his body moving through the dense liquid, created a localized hydrostatic shockwave. The displaced water surged forward, hitting the jellyfish before Izuku's net even reached them. The poor creatures were violently spun out of control, sent tumbling through the water like leaves in a hurricane. 

"Ah!" Izuku yelped, trying to brake, but his momentum carried him forward, sending him crashing face-first into a large, spongy pink coral reef. 

He groaned, pulling himself out of the coral, rubbing his nose. 

SpongeBob swam over, looking concerned. "Wow, Green Barnacle! You're fast! But you're fighting the water. You can't punch the ocean, silly! You have to flow with it."

SpongeBob placed his hands on his hips. "When a jellyfish moves, it doesn't fight the current. It rides it. You’re too tense! You’re stiff like a frozen Krabby Patty! You need to be soft, like a freshly baked bun."

Izuku paused. Flow with it. Don't fight the current. It was surprisingly profound advice, echoing the teachings of Gran Torino when Izuku was learning to bounce off walls without losing momentum. In the air, he used the walls to redirect his kinetic energy. In the water, the water was the wall. He needed to use the resistance, not overpower it. 

"Let's try again," Izuku said, determination burning in his green eyes. He powered up Full Cowling again, but this time, he lowered the output to three percent. He didn't need raw power; he needed control. 

He spotted a lone, large jellyfish drifting near a kelp forest. 

Instead of launching himself like a missile, Izuku bent his knees and pushed off lightly. He let the natural buoyancy of the water carry him upward, keeping his body streamlined. As he approached the jellyfish, he didn't swing the net violently. He extended his arm and used a quick, subtle burst of One For All in his wrist to snap the net forward, letting the water current naturally guide the jellyfish into the pouch. 

Bloop.

He caught it. 

Izuku landed softly on a rock, holding the net up. The jellyfish buzzed peacefully inside. 

"I did it!" Izuku cheered, a massive smile breaking across his face. 

"Hooray!" SpongeBob cheered, clapping his hands. "You're a natural, Green Barnacle! Your agility is off the charts! Now, for phase two of your training: Close Quarters Combat!"

Phase two took them back to Sandy’s Treedome, though this time they remained outside the glass, standing in a large clearing of sand. Sandy was waiting for them, clad in her bulky, white atmospheric diving suit, her glass dome gleaming in the filtered sunlight. 

"So, the little green bean wants to learn how to fight, Texas style?" Sandy grinned, punching her thick gloves together. "I gotta warn ya, I've wrangled bull-worms bigger than you, kid."

"Don't underestimate him, Sandy!" SpongeBob cheered from the sidelines, wearing a foam finger that said '1 Sidekick'. "He's got the glowing green Christmas lights of justice!"

Izuku bowed deeply to Sandy. He had deactivated his cowl, letting his green hair float freely in the water. "I appreciate the opportunity to spar, Sandy. I need to test my hand-to-hand capabilities in a zero-gravity, high-resistance environment."

"Right. Whatever that means," Sandy chuckled. "Let's see what you got. Kah-rah-tay!"

Sandy lunged forward. For a creature in a massive, pressurized suit, she was impossibly fast. She utilized a martial arts style Izuku had never seen—a mix of terrestrial karate, judo, and what appeared to be rodeo roping techniques. 

She threw a right hook. 

Izuku ducked under it, activating Full Cowling at five percent. He moved to sweep her legs, aiming for the joints of her suit, but Sandy anticipated it. She planted her hands on the sand and used the water resistance to perform a slow-motion, floating backflip over his leg, aiming a downward heel kick at his shoulder. 

Izuku crossed his arms, blocking the blow. The impact sent a shockwave through the water, pushing him back a few feet, his iron soles scraping the sand. 

She's strong! Izuku noted, his analytical brain firing on all cylinders. Her suit adds immense mass, but she uses the water's buoyancy to negate the weight while retaining the kinetic energy of her strikes. She fights in complete three-dimensional space, unbound by gravity.

"Not bad, kid!" Sandy laughed, launching a flurry of chops. "But you're too grounded! You're fightin' like you're still on dry land!"

Sandy was right. Izuku was instinctively trying to keep his feet on the ground to generate power from his hips, just like All Might had taught him. But underwater, that severely limited his mobility. 

I need to take to the air... or, the water, Izuku realized. 

He didn't plant his feet this time. As Sandy threw a punch, Izuku leaped upward, letting himself float freely. He used a burst of One For All in his left arm to create a small, localized air-pressure blast—not at Sandy, but behind himself. The recoil propelled him forward in mid-water, allowing him to circle around Sandy in a dizzying arc. 

"Detroit..." Izuku muttered, pulling his right leg back. He didn't want to hurt her, so he aimed for the dense titanium plating on the back of her suit. "...Smash!"

He delivered a controlled, five-percent kick. The blow connected with a loud, metallic CLANG that echoed through the water. Sandy was sent tumbling forward, doing three somersaults before catching herself and landing on her feet. 

She stood up, dusting off her suit. She looked at Izuku, her eyes wide behind her glass dome. Then, a massive grin spread across her face. 

"Hot dog!" Sandy cheered. "Now that's a kick! You pack the punch of a buckin' bronco, kid! If you weren't holdin' back, you might have dented my suit!"

"I'm sorry! I didn't mean to hit that hard!" Izuku panicked, immediately bowing in apology, waving his hands frantically. 

"Are you kiddin'? That was awesome!" Sandy laughed, walking over and clapping him on the shoulder, nearly knocking him into the sand. "You got a good head on your shoulders, Green Barnacle. You learn fast. You use the environment instead of fightin' it."

"He's ready!" SpongeBob declared, marching over and blowing a small whistle he produced from nowhere. "Agility? Mastered! Combat? Mastered! Now, it is time for the final, and most grueling test of a hero."

SpongeBob’s face grew deadpan, a shadow seemingly casting over his features despite the bright sunlight. 

"Endurance. Fortitude. The ability to perform under the most intense, soul-crushing pressure known to fish-kind."

Izuku swallowed hard, clenching his fists. A torture endurance test? A simulation of a villain hostage situation? "I'm ready, Invincibubble. What is it?"

SpongeBob pointed dramatically into the distance. "The Lunch Rush at the Krusty Krab."

If Izuku had thought the USJ attack was stressful, it paled in comparison to the culinary warzone that was the Krusty Krab at 12:30 PM on a Tuesday. 

The restaurant, a building shaped like a wooden lobster trap, was packed to the gills. Dozens of hungry, angry fish were shouting orders, banging on tables, and complaining about the wait times. Behind the register stood a miserable-looking squid with a massive nose, who was completely ignoring the chaos in favor of reading a magazine called House Fancy. 

And standing in the center of the dining room was the proprietor, a large, red crab wearing a blue shirt and trousers. His eyes extended from the top of his head on long stalks. 

"Move it, move it, move it!" Mr. Krabs roared, his claws snapping in the air. "Time is money, and you barnacle-heads are costin' me both! SpongeBob! I need ten Krabby Patties, five orders of Coral Bits, and a Kelp Shake on the double!"

"Aye aye, Captain!" SpongeBob saluted. He turned to Izuku, who was standing awkwardly near the kitchen doors, looking completely overwhelmed. SpongeBob had outfitted him in a white paper Krusty Krab hat, which sat precariously between the green, bunny-like 'ears' of his cowl. 

"Alright, Green Barnacle," SpongeBob said, his tone dead serious. "This is it. The ultimate test of stamina. Mr. Krabs kindly agreed to let you train here as an unpaid intern."

Unpaid intern, Izuku thought, a sweatdrop forming on his brow. He's exploiting a stranded interdimensional traveler for free labor. 

Izuku analyzed the red crab. Crustacean mutation. Likely possesses immense physical strength in those claws. Wait, his eyes are dollar signs right now. Is that a Quirk, or just a cartoonish exaggeration of his greed?

"Listen to me, boy," Mr. Krabs said, marching over and pointing a large red claw at Izuku's chest. "I don't care if you're a superhero, a mutant, or a green bean with legs. In my restaurant, you follow orders. You deliver the food hot, you don't drop the trays, and you NEVER give out free refills! You got that?"

"Y-yes sir!" Izuku saluted nervously. 

"Then get in the kitchen and start flipping!" Krabs bellowed. 

Izuku rushed through the swinging doors into the kitchen. It was hot, greasy, and smelled incredibly delicious. The grill was sizzling. SpongeBob was already there, moving at a speed that defied comprehension. The sponge was a blur of yellow, his arms multiplying as he simultaneously flipped patties, chopped onions, squirted ketchup, and toasted buns. 

"Order up!" SpongeBob yelled, tossing a perfect, steaming Krabby Patty onto a plate. "Table four, Green Barnacle! Go, go, go!"

Izuku grabbed the plate. He needed to be fast. He activated Full Cowling at three percent. He burst through the kitchen doors, zipping across the dining room in a flash of green lightning, dodging a waitress holding a tray of drinks, sliding under a table, and placing the plate perfectly in front of a startled blue fish. 

"Enjoy your meal!" Izuku said rapidly, bowing, before zipping back into the kitchen. 

"Amazing!" SpongeBob cheered. "But can you handle... The Multi-Order?"

SpongeBob tossed four plates into the air. 

Izuku caught them all, balancing them on his arms. He dashed out again. For the next two hours, Izuku Midoriya was pushed to his absolute physical and mental limits. It wasn't about fighting villains; it was about precision, spatial awareness, and endless repetition. He used One For All to navigate the crowded room, his analytical mind calculating the optimal routes between tables to avoid collisions. He learned to anticipate the orders, to read the body language of the customers to know when they needed napkins or extra ketchup. 

It was exhausting. His legs burned, his lungs heaved, and his hero costume was covered in a fine layer of fry-grease. 

But as he worked alongside SpongeBob, he noticed something. 

No matter how rude the customers were, no matter how much Mr. Krabs yelled, SpongeBob never lost his smile. The sponge treated every single Krabby Patty like it was a masterpiece, a precious artifact to be handled with love and care. 

During a brief lull in the rush, Izuku leaned against the stainless steel counter, wiping sweat from his forehead. "SpongeBob... how do you do it? How do you keep up this level of energy? This isn't saving the world. It's just... fast food."

SpongeBob stopped scrubbing the grill for a moment. He looked at the spatula in his hand, a soft, fond smile on his face. 

"Deku," SpongeBob said quietly, using Izuku's real hero name. "When a fish comes in here, they might be having the worst day of their life. Maybe they lost their job. Maybe they stubbed their toe. But when they take a bite of a Krabby Patty... for just a few minutes, everything is perfect. They smile."

SpongeBob looked up, his large blue eyes meeting Izuku's green ones. "You save people by fighting bad guys. I save people by filling their tummies with joy. It doesn't matter what your job is. If you're doing it to make someone else's life a little brighter... then you're a hero in my book."

Izuku stared at the sponge. The words hit him harder than any physical blow he had ever taken. It was the core essence of All Might’s philosophy, stripped of all the glamour and superpowers, applied to the most mundane job in the world. 

He's right, Izuku thought, a profound respect blooming in his chest. Heroism isn't just about punching villains. It's about service. It's about the smile.

"You're an amazing hero, SpongeBob," Izuku said sincerely. 

"And you're an amazing sidekick, Green Barnacle!" SpongeBob cheered, throwing an arm around Izuku. "We survived the lunch rush! Nothing can stop us now!"

As if on cue, the universe decided to test that theory. 

The floor of the kitchen suddenly pitched violently upward. Izuku lost his footing, crashing into the counter as a deafening, earth-shattering BOOM echoed from the street outside. The lights in the Krusty Krab flickered and died, plunging the restaurant into dim, watery shadows. 

Screams erupted from the dining room. 

"What was that?!" Izuku shouted, instantly dropping his spatula and dropping into a combat stance, the green lightning of One For All flaring to life around him. 

SpongeBob’s eyes went wide. He grabbed his spatula, holding it like a sword. "That sounded like it came from outside!"

Izuku kicked the kitchen doors open, rushing into the dining room. Mr. Krabs was cowering behind the cash register, clutching a cash box to his chest. The customers were in a panic, pointing toward the massive glass windows at the front of the restaurant. 

Through the glass, the normally clear, sunlit waters of Bikini Bottom were choked with a massive, dark cloud of churned-up sand and debris. Sirens began to wail in the distance, a haunting, high-pitched aquatic howl. 

Slowly, the dust began to settle. 

Across the street, the metal doors of the Chum Bucket had been blown completely off their hinges. Standing in the doorway, silhouetted by the eerie green light of Plankton's laboratory, was a massive, hulking figure. 

It was easily nine feet tall. Its body was grotesquely muscular, a sickening, lumpy amalgamation of dark red chum, robotic sentry parts, and thick, ropy kelp acting as veins. It had a metal jaw ripped from a U.A. training robot, and its brain was completely exposed at the top of its head, encased in a reinforced glass dome. 

"Is... is that a Nomu?" Izuku whispered, his blood running cold. 

The monster raised its head and let out a deafening, metallic roar that shattered the front windows of the Krusty Krab, sending glass cascading into the dining room. 

Standing on the monster's shoulder, holding a tiny megaphone, was Sheldon J. Plankton. 

"Attention, citizens of Bikini Bottom!" Plankton's voice boomed over the chaos. "And more importantly, attention Eugene Krabs! Your days of fast-food monopoly are over! Hand over the Krabby Patty Secret Formula, or my Chum-Nomu will tear this miserable restaurant down to the foundation!"

Izuku stepped forward, stepping past the terrified fish. The playful, analytical boy was gone. The hero had arrived. He glared through the broken window at the abomination outside, his fists clenching tightly. 

"SpongeBob," Izuku said, his voice low, steady, and devoid of fear. "Training's over."

SpongeBob stepped up beside him, his spatula raised, his face set in an expression of uncharacteristic, fierce determination. "I'm ready, Green Barnacle. Let's go save the Krusty Krab."

The silence that followed the Chum-Nomu’s roar was absolute, a heavy, suffocating blanket that fell over the Krusty Krab. For a split second, the only sound was the gentle clinking of shattered glass settling onto the wooden floorboards of the dining room. 

Then, total pandemonium erupted. 

"MY LEG!" a green fish screamed, scrambling over a splintered table. 

The patrons of the Krusty Krab, usually only concerned with the timely arrival of their meals, devolved into a terrified, stampeding mob. Trays of food were abandoned, half-eaten Krabby Patties trampled into the floorboards as dozens of aquatic citizens bolted for the rear emergency exit. 

Izuku Midoriya didn’t panic. The moment the window shattered, his U.A. training overrode his shock. He was no longer a stranded teenager; he was a Pro Hero in training. 

"Everyone, stay calm! Evacuate through the rear exit in an orderly fashion!" Izuku barked, his voice projecting with the authority he had watched Tenya Iida use time and time again. He activated One For All: Full Cowling at a mere two percent—just enough to give him the speed needed to assist the stragglers. He zipped across the room, catching a falling beam before it could crush an elderly lady fish with a walker, gently setting it aside and guiding her toward the door. 

"SpongeBob!" Izuku called out over his shoulder. "Make sure the kitchen is clear! Cut the gas lines to the grill to prevent secondary explosions!"

"Aye aye, Green Barnacle!" SpongeBob yelled back, entirely bypassing his usual panic in favor of sidekick duty. He zipped into the kitchen, his spatula spinning like a propeller. 

Izuku turned his attention back to the massive hole in the front of the restaurant. The dust in the water was beginning to clear, revealing the horrifying silhouette of the beast standing across the street. 

Izuku’s emerald eyes narrowed, his mind immediately breaking down the creature’s anatomy. 

It’s easily over three meters tall, Izuku calculated, his breathing steadying despite the adrenaline coursing through his veins. The musculature is hyper-developed, completely disproportionate to any natural biological growth. It mimics the bio-engineered structure of the Nomu created by the League of Villains, but the composition is wrong. It’s not human DNA. It’s dark red, gelatinous... it smells like rotting organic waste. Chum. The villain, Plankton, mentioned chum. He used the stolen U.A. Support Gear to bind the biological mass together! 

Izuku’s gaze snapped upward to the creature's exposed brain, encased in a thick glass dome. And there's the control center. Just like the USJ Nomu. If it shares the same base characteristics, it likely possesses immense physical strength and Shock Absorption.

Standing atop the glass dome, gripping a makeshift joystick wired directly into the creature’s cerebral cortex, was Plankton. The tiny, one-eyed villain was cackling madly, his maniacal laughter amplified by the megaphone strapped to his side. 

Behind the beast, standing in the ruined doorway of the Chum Bucket, was the smuggler Rift. The MHA villain looked exhausted, his hands bound by glowing, high-tech energy cuffs that tethered him to a massive, sputtering generator inside Plankton’s lab. Rift’s spatial-distortion Quirk was still active, though the portal behind him had shrunk to a pulsating, unstable tear just a few feet wide. 

"Behold, Eugene!" Plankton’s voice thundered across the street. "You’ve mocked my Chum for years! You claimed it was inedible! You claimed it was biological waste! Well, you were right! But mixed with the terrifying science of another dimension, it has become the instrument of your doom! I call it... the Chum-Nomu!"

Mr. Krabs peeked his eyestalks over the edge of the cash register boat. His claws were trembling, but a furious scowl twisted his face. "You’ll never get the formula, Plankton! I’d sooner eat me own shell!"

"We’ll see about that!" Plankton sneered. He pushed the joystick forward. 

The Chum-Nomu let out another gurgling, metallic roar. It took a single step forward. The sheer weight of the creature caused the sandy seabed to crater beneath its foot. The shockwave of the step traveled through the water, rattling the remaining intact windows of the Krusty Krab. 

"Stop right there!" 

Izuku stepped out of the ruins of the Krusty Krab, planting his iron-soled boots firmly into the sand of the street. The green lightning of One For All crackled violently around his body, illuminating the murky water with a neon glow. 

Plankton blinked his single eye, squinting down at the green-haired boy. "What in the name of Neptune is that? Some kind of radioactive kelp-boy? Are you a new mascot, Krabs? Because he looks ridiculous!"

"I am a Pro Hero in training," Izuku declared, dropping into a low combat stance. "And I won't let you terrorize these people or steal from this establishment. Surrender now, Plankton!"

"A hero?" Plankton laughed, a high, grating sound. "The only heroes in this town are two senile old men in a retirement home! Chum-Nomu! Crush the kelp-boy!"

The monster didn't hesitate. It lunged forward with terrifying speed, closing the distance between the Chum Bucket and the Krusty Krab in a fraction of a second. It raised a massive, chum-covered fist, reinforced with the metal plating of a U.A. security bot, and brought it down toward Izuku. 

Izuku reacted on pure instinct. Full Cowling - Eight Percent!

He channeled the power into his legs and pushed off the ground, intending to dodge backward. But as his muscles fired, Izuku collided with the harsh reality of deep-sea combat. 

On dry land, an eight-percent jump would have sent Izuku hurtling backward through the air in the blink of an eye. But here, submerged in thousands of tons of water, the fluid resistance acted like a massive, invisible wall. His legs moved fast, but his body was delayed by the drag of the ocean. 

He didn't clear the blast radius. 

The Chum-Nomu’s fist slammed into the seabed where Izuku had just been standing. The physical impact was deafening, but the hydrostatic shockwave was devastating. The kinetic energy displaced the water so violently that it created a localized concussive blast. 

Izuku was caught in the wave. The water hit him like a solid brick wall, slamming into his chest and sending him tumbling end-over-end through the ocean. He crashed violently into a streetlamp, the metal pole bending under his weight. 

He gasped, a bubble of precious air escaping his lips before the Gilly-Patch on his throat hummed, forcing more oxygen into his lungs. His ribs throbbed with agonizing pain. 

It’s fast, Izuku winced, pushing himself off the bent pole. But it’s not just its speed. The water isn't slowing it down. Its mass is so incredibly dense, and its machinery so powerful, that it’s completely overcoming the fluid drag!

The Chum-Nomu turned its featureless, horrifying face toward Izuku, letting out a mechanical hiss. 

"Ha! Is that all you’ve got, kelp-boy?!" Plankton cheered from his perch. "My Chum-Nomu is unstoppable! It has the strength of a hundred men and the smell of a thousand dumpsters!"

Izuku wiped a small trail of blood from the corner of his mouth. He needed to go on the offensive. He couldn't let it near the restaurant. 

If I can’t dodge effectively, I have to overpower it, Izuku calculated. But I can't use 100%. The cavitation bubble created by a 100% smash underwater would instantly boil the water around me from the friction and create a concussive blast strong enough to level half of Bikini Bottom. I need a concentrated, mid-range attack.

"Hold on, Green Barnacle! I’m coming!" 

A yellow blur shot out of the Krusty Krab. SpongeBob landed next to Izuku, striking a heroic pose. He was no longer just wearing his paper hat; he had donned his purple towel cape and the metal colander helmet. But more importantly, strapped around his waist was a bright yellow utility belt featuring a massive gold buckle shaped like an 'M'. 

"SpongeBob! It's too dangerous!" Izuku warned, throwing his arm out to shield his friend. "This villain is modeled after a bio-weapon from my world. Its physical strength is off the charts!"

"Fear not, citizen!" SpongeBob declared, his voice dropping an octave in a poor imitation of a classic superhero. "For I have borrowed the sacred relic of justice! The Mermaid Man Utility Belt!"

Plankton squinted at the belt. "Wait a minute... is that the real deal? How did you get that, you porous freak?!"

"Mermaid Man left a spare key under the doormat of the Mermalair!" SpongeBob explained proudly. "Now, stand back, Green Barnacle! I shall vanquish this foul beast with the power of the Shrink Ray!"

SpongeBob thrust his hips forward, pointing the 'M' buckle directly at the Chum-Nomu. He pressed a button on the side of the belt. 

ZAP!

A beam of crackling blue energy shot from the buckle. But SpongeBob, in his excitement, hadn't checked the settings. 

The beam missed the Chum-Nomu entirely, ricocheting off a piece of floating debris and striking a figure who had just crept out of the side door of the Krusty Krab, desperately trying to sneak away from the battle. 

It was Squidward Tentacles. 

"I am not getting paid enough to die to a pile of chum today—" Squidward muttered, right before the blue beam hit him square in the chest. 

With a comedic POP, the cynical octopus instantly shrank down to the size of a thimble. 

"What the...?" Squidward’s voice was now incredibly high-pitched and squeaky. He looked up at the towering kelp plants and the massive grains of sand. "Oh, you have got to be kidding me. SpongeBob! You imbecile!"

"Oops!" SpongeBob gasped, looking down at his belt. "I forgot! The belt is set to 'M' for Mini! I need to set it to 'W' for Wumbo!" 

SpongeBob frantically tried to twist the buckle upside down, fumbling with the heavy gold 'M'. 

"He's distracted!" Plankton yelled. "Squash the sponge!"

The Chum-Nomu leaped forward, raising both fists over its head for a devastating double-hammer blow. 

"SpongeBob, move!" Izuku screamed. 

Knowing his friend wouldn't dodge in time, Izuku pushed One For All to fifteen percent. He couldn't worry about the water resistance now. He lunged forward, tackling SpongeBob out of the way just as the Chum-Nomu’s fists slammed into the ocean floor. 

The resulting shockwave was massive. The seabed ruptured, sending a massive cloud of sand and debris exploding upward into the water. Izuku and SpongeBob were thrown backward, tumbling through the aquatic dust storm. 

Izuku dug his iron soles into the sand, skidding to a halt. The water was completely opaque with churned-up mud. Visibility was zero. 

I can't see it, Izuku panicked, his eyes darting through the murky brown water. But I can feel the current shifting!

"Detroit..." Izuku muttered, pulling his right arm back. He focused the power of One For All entirely into his fist, wrapping it in dense, crackling green energy. He felt the water pressure shift slightly to his left—the beast was flanking him in the dust cloud. 

Izuku spun around, unleashing a fifteen-percent punch directly into the murk. "...SMASH!"

His fist collided with something incredibly dense. The sheer force of the blow created a massive cavitation bubble—a vacuum in the water born from extreme speed and pressure. The bubble instantly collapsed with a deafening CRACK, producing a flash of heat and light that cleared the sand cloud in an instant. 

Izuku’s eyes widened in horror. 

His fist was buried deep into the center of the Chum-Nomu’s chest. But the beast hadn't been blown away. The dense, gelatinous mixture of chum and bio-engineered muscle had acted like a massive, disgusting sponge. It had absorbed the kinetic energy of the Smash, rippling violently as the force was dispersed throughout its massive body. 

The Chum-Nomu didn't even flinch. It looked down at Izuku, its exposed brain pulsating with an eerie green light. 

Shock Absorption, Izuku realized, terror gripping his heart. It’s perfectly mimicking the USJ Nomu. Physical attacks are completely nullified!

"Ha!" Plankton cheered, doing a little dance on the glass dome. "Your parlor tricks are useless against my genius! Now, rip him apart!"

The Chum-Nomu raised its massive hand and swatted Izuku like a pesky fly. 

The blow was catastrophic. Izuku felt ribs crack as he was launched through the water at blistering speed. He crashed through the large wooden pole holding up the Krusty Krab’s clamshell sign, snapping it in half, before skipping across the asphalt street like a skipped stone, finally coming to a halt in a pile of crushed coral. 

"DEKU!" SpongeBob screamed, abandoning his superhero persona in sheer panic. 

SpongeBob rushed forward, stepping between the fallen hero and the towering monster. He raised his fists, his body trembling, but his eyes blazing with defiance. 

"Leave him alone, Plankton!" SpongeBob yelled. "If you want to get to him, you have to go through me! And I am a very highly trained fry cook!"

"Gladly," Plankton sneered. "Flick the sponge."

The Chum-Nomu extended a single, massive finger and flicked SpongeBob square in the chest. 

Unlike Izuku, SpongeBob’s body was perfectly designed for this. The kinetic energy of the flick hit the sponge, and SpongeBob’s body instantly depressed, wrapping around the giant finger like a deflated balloon, absorbing the blow entirely without taking a shred of physical damage. 

However, the sheer momentum was still transferred. SpongeBob was launched backward like a cannonball, screaming as he sailed over the Krusty Krab, flying completely out of sight toward the residential district of Bikini Bottom. 

"Sponge... Bob..." Izuku choked out, trying to push himself up from the rubble. Every muscle in his body screamed in agony. The Gilly-Patch on his throat was working overtime, pumping oxygen into his gasping lungs. 

"Now that the pests are dealt with," Plankton announced, turning the Chum-Nomu toward the ruined storefront of the Krusty Krab. "It’s time to claim my prize! Rip the safe open!"

The Chum-Nomu marched into the restaurant. Mr. Krabs was standing in front of his office door, holding a wooden broom like a spear. 

"Over me dead body, you one-eyed parasite!" Mr. Krabs roared, charging forward. He swung the broom with surprising speed, snapping it against the Chum-Nomu’s kneecap. 

The beast didn't react. It simply reached down, grabbed Mr. Krabs by his hard outer shell, and lifted the struggling crab into the air. 

"Hey! Put me down! I'll pinch ya! I'll give ya the clamps!" Mr. Krabs yelled, his claws snapping frantically against the monster’s impenetrable hide. 

"Bring him with us," Plankton commanded, his eye gleaming with triumph. "He can watch as I mass-produce his precious formula! Now, get the safe!"

The Chum-Nomu reached into Mr. Krabs' office. Its massive fingers dug into the reinforced steel of the safe as easily as if it were made of wet cardboard. With a horrific screech of tearing metal, the beast ripped the entire safe out of the floor. It smashed the door open, revealing a single, glass bottle containing a piece of rolled-up parchment. 

The Krabby Patty Secret Formula. 

Plankton gazed at it, tears of evil joy welling in his single eye. "At last... after all these years. It’s mine! IT’S FINALLY MINE!"

Izuku watched from the street, his vision blurring. He forced One For All into his broken body, trying to stand. I have to... stop him. I can't let a villain win. I can't...

He managed to stagger to his feet, green lightning weakly sparking around his arms. But before he could take a step, his left leg gave out, and he collapsed back into the sand. 

"Retreat to the Chum Bucket!" Plankton ordered. "And seal the blast doors!"

The Chum-Nomu, carrying the safe in one hand and the thrashing Mr. Krabs in the other, turned and marched back across the street. It stepped over the threshold of the Chum Bucket. 

Rift, still chained to the generator, looked at the approaching monstrosity with pure terror. "You got what you wanted! Now let me go!"

"Patience, my dimensional friend," Plankton cackled as the Chum-Nomu stomped inside. "The fun is just beginning!"

With a heavy, mechanical groan, the massive steel blast doors of the Chum Bucket slid shut, locking with a definitive, echoing CLANG. 

The street fell silent once more, save for the distant wailing of sirens. 

Izuku lay in the rubble, staring at the sealed doors of the Chum Bucket. The taste of copper filled his mouth. The cold of the ocean seemed to seep into his very bones, bypassing his Gilly-Patch, chilling his soul. 

He had lost. 

It wasn't just a sparring match. It wasn't a training exercise. A villain had attacked, stolen something precious, kidnapped a civilian, and Izuku had been completely, utterly powerless to stop it. The Shock Absorption Quirk of the Nomu was a hard counter to his brawler fighting style, and the underwater physics had neutralized his speed and agility. 

He was useless. 

Memories, dark and insidious, began to bubble up from the depths of his mind. The mocking laughter of his middle school classmates. Bakugo’s explosive threats. The hollow, sinking feeling in his chest when the doctor told him he was Quirkless. The agonizing realization that he was just a Deku—a useless wooden doll that couldn't do anything. 

Tears welled in Izuku’s eyes, mixing instantly with the salty ocean water. He pulled his knees to his chest, burying his face in his arms. 

All Might entrusted me with this power, Izuku thought, his shoulders shaking with silent sobs. He gave me everything. And I can't even protect a fast-food restaurant. What kind of hero am I? I'm pathetic. I'm just playing dress-up.

Footsteps padded softly against the sand. 

Izuku didn't look up. He didn't want the police or the paramedics to see him crying. He just wanted to disappear. 

But it wasn't the police. 

A gentle, squishy hand rested on Izuku’s shoulder. 

Izuku flinched, looking up. 

SpongeBob was standing beside him. The sponge looked battered. His square pants were torn, his white shirt was covered in soot and sand, and his purple towel cape was in tatters. He was bruised and missing one of his shiny black shoes. 

But he wasn't crying. 

SpongeBob sat down in the sand next to Izuku, crossing his spindly legs. He reached into his pocket and pulled out a small, carved piece of wood. It was a nose-flute. 

Without a word, SpongeBob placed the flute under his nose. He took a deep breath and began to play. 

The melody was incredibly melancholic, a high, mournful tune that perfectly captured the devastating sadness of the moment. It was a cartoonish gesture, absolutely absurd in the context of a superhero failure, but there was a deep, genuine soulfulness to the music that caught Izuku completely off guard. 

The sad, beautiful notes drifted through the water, echoing off the ruined shell of the Krusty Krab. 

Izuku wiped his eyes, sniffing. "SpongeBob... I'm so sorry. I failed. I failed you, I failed Mr. Krabs... I couldn't stop it."

SpongeBob stopped playing. He lowered the flute, looking at the Chum Bucket. 

"You know, Green Barnacle," SpongeBob said softly, his voice devoid of its usual manic energy. "Mermaid Man didn't always win."

Izuku blinked, surprised. "He didn't?"

"Nope," SpongeBob shook his head, looking down at his lap. "I have every comic book. I know all the stories. There was an issue—Issue 45, 'The Day the Bubble Burst'—where the Dirty Bubble captured Barnacle Boy and trapped the entire city in an impenetrable sphere of soap. Mermaid Man tried everything. He punched it, he threw waterballs at it, he even tried negotiating with it. But nothing worked. He was beaten."

SpongeBob looked up, his large blue eyes meeting Izuku’s. 

"Mermaid Man sat on a rock, and he cried. Just like you. He thought he wasn't a hero anymore. He thought he was just an old man in a seashell bra."

Izuku swallowed hard, captivated by the story. "What... what did he do?"

"He remembered who he was," SpongeBob smiled faintly. "He remembered that a hero isn't measured by how hard they can punch, or how fast they can swim. A hero is measured by what they do after they get knocked down. Mermaid Man realized he couldn't break the bubble from the outside. So, he built a giant mechanical needle, launched himself into the bubble’s core, and popped it from the inside out."

SpongeBob reached out, taking Izuku’s bruised hand in his soft, spongy ones. 

"Deku, you are the bravest person I have ever met," SpongeBob said, his voice trembling with absolute, unwavering sincerity. "You fell out of the sky, into a world you don't understand, and you didn't hesitate for one second to put yourself between me and that monster. You got hurt to protect me."

SpongeBob stood up, his face hardening with a fierce, burning resolve that Izuku had never seen on a cartoon character before. 

"We lost a battle," SpongeBob declared, pointing a finger at the Chum Bucket. "But we haven't lost the war! Mr. Krabs is in there. The formula is in there. And as long as I have breath in my spongy lungs, I will never stop fighting for the Krusty Krab!"

SpongeBob turned to Izuku, offering his hand. 

"We don't need to be the strongest, Deku," SpongeBob smiled, a bright, radiant expression that rivaled the sun itself. "We just need to be ready! Are you ready?"

Izuku stared at the yellow hand extended toward him. 

The darkness in his mind shattered. The crippling self-doubt, the lingering echoes of his Quirkless past, were washed away by a tidal wave of pure, unfiltered optimism. SpongeBob didn't care about Quirks. He didn't care about power levels or Shock Absorption. He only cared about doing the right thing. 

He's right, Izuku realized, a fire igniting in his chest. I was focusing entirely on my Quirk. I was trying to fight a brute-force battle against a creature designed for brute force. I forgot what makes me a hero. I forgot my mind.

Izuku reached out, gripping SpongeBob’s hand. 

"I'm ready," Izuku said. 

SpongeBob hauled him to his feet. Izuku winced as his ribs flared with pain, but he ignored it. He reached into his pouch and pulled out his ruined, waterlogged notebook. He didn't need it. The calculations were already running through his head. 

"We need a plan," Izuku said, his voice dropping into its rapid-fire analytical cadence. "The Chum-Nomu has Shock Absorption. Blunt force trauma is ineffective. But it's not invincible. Plankton made a fatal flaw when he engineered it."

"He did?" SpongeBob asked, his eyes wide. 

"Yes," Izuku nodded, his emerald eyes locking onto the Chum Bucket. "He made it out of Chum. Biological waste. And more importantly, he bound it together using deep-sea water pressure and chemical adhesives. It's essentially a giant, gelatinous mass."

Izuku looked at SpongeBob. "Invincibubble... what happens to a sponge when you leave it out in the sun, or when it gets too hot?"

SpongeBob gasped, realizing what Izuku was implying. "It dries out! It becomes stiff, and brittle, and it crumbles!"

"Exactly," Izuku grinned, a fierce, heroic smile breaking across his bruised face. "If we can subject the Chum-Nomu to extreme, localized heat, we can bypass its Shock Absorption entirely. We can dry out the chum, neutralize its muscular structure, and shatter it."

"But how are we going to generate heat underwater?" SpongeBob asked, scratching his head. "Sandy's the only one with fire, and she's busy building your portal machine!"

"I can generate heat," Izuku said, staring at his hands. "If I focus One For All to high percentages, the friction of my movements creates intense heat. But underwater, the resistance slows me down too much to generate the necessary speed, and the water instantly cools the attack."

Izuku looked at the ground, thinking furiously. "I need a way to move at one hundred percent speed underwater, without the water drag slowing me down. I need..."

"You need to move like a fish!" SpongeBob snapped his fingers. "Or better yet... a superhero of the sea!"

SpongeBob grabbed the utility belt around his waist. "Green Barnacle! I didn't just borrow the belt from the Mermalair. I brought the whole arsenal! And I know exactly what you need to go fast!"

"Really?" Izuku asked, hope flaring in his chest. 

"Follow me!" SpongeBob cheered, turning and sprinting down the street toward a dark, imposing cave entrance nestled between two coral reefs. "To the Mermalair! We've got a rescue mission to plan, and a very tiny, very evil genius to squash!"

Izuku Midoriya took a deep breath, the oxygen from the Gilly-Patch fueling his resolve. The pain in his body faded, replaced by the crackling green energy of One For All. He wasn't Deku the failure. He was the Green Barnacle, and he had a sidekick to keep up with. 

With a burst of green lightning, Izuku chased after his friend, ready to take the fight to the Chum Bucket.

The aquatic cavern was shrouded in absolute darkness, the kind of deep-sea pitch black that swallowed light and sound alike. For Izuku Midoriya, trailing behind a battered but inexplicably cheerful sea sponge, the descent into the hidden cave system was both nerve-wracking and incredibly fascinating. 

"Watch your step, Green Barnacle!" SpongeBob’s voice echoed off the damp, algae-covered stone walls. "The Mermalair’s security systems are highly advanced! We wouldn't want to trigger the Barnacle-Bolters, or worse, the Tickle-Tanks!"

Izuku walked carefully, his iron-soled boots clicking softly against the rocky uneven floor. He had One For All humming at a low two percent, just enough to let the ambient green lightning illuminate their path. The green glow cast eerie, shifting shadows across the stalactites hanging from the cavern ceiling. 

"SpongeBob, are you sure we're allowed to be down here?" Izuku asked, his inherent respect for rules and authority making him hesitant. "In my world, entering a Pro Hero's agency or secret base without explicit clearance is a severe violation of the Hero Public Safety Commission's bylaws. We could be arrested for trespassing."

"Pish-posh!" SpongeBob waved a hand dismissively, not looking back. "Mermaid Man and I are like this!" He crossed two of his spongy fingers. "I'm the president of the Mermaid Man and Barnacle Boy Fan Club! Besides, this is a state of emergency. When evil rears its ugly, single-eyed head, justice doesn't wait for paperwork!"

Izuku couldn't argue with that logic. Plankton had stolen a critical asset, kidnapped a civilian, and unleashed a bio-engineered nightmare on the city. There was no time to wait for the authorities. 

Still, Izuku thought, his mind whirring as he analyzed their surroundings, this cave system is remarkably well hidden. The entrance was obscured by a dense thicket of brain coral and a localized thermal vent that masked any thermal imaging. A perfect natural cloaking mechanism.

"Ah! Here we are!" SpongeBob announced, coming to a sudden halt. 

Izuku bumped into him, looking over the sponge's square shoulder. They were standing at the edge of a massive, seemingly bottomless chasm. Across the gap, a smooth, metallic wall was built seamlessly into the rock face, featuring a massive, rusted steel door embossed with a giant red 'M'. 

"The front door," SpongeBob whispered reverently. 

"How do we get across?" Izuku asked, peering into the abyss. "I could try to carry you and jump, but my footing is still compromised by the water drag—"

"No need, Green Barnacle! We use the secret access terminal!" SpongeBob reached into a crevice in the cave wall and pulled out what looked exactly like a standard, surface-world doorbell. It was inexplicably dry and glowing with a faint yellow light. 

SpongeBob pressed it. 

Instead of a chime, a loud, pre-recorded voice that sounded like a very old, very tired man screamed, "EVIL! EVIL IS APPROACHING! BARNACLE BOY, MAN THE TARTAR SAUCE CANNONS!"

The metallic wall across the chasm groaned. A hidden compartment slid open, and a massive, mechanical hand shot out across the gap. It didn't attack them; rather, it gently scooped both Izuku and SpongeBob up into its palm and retracted, pulling them smoothly through a hidden slot in the steel door. 

Izuku squeezed his eyes shut, bracing for a trap, but instead, he was deposited softly onto a plush, red velvet carpet. 

He opened his eyes. 

The breath caught in his throat. His Gilly-Patch whirred as it compensated for his sudden gasp. 

"Welcome, sidekick," SpongeBob said, striking a heroic pose with his tattered towel-cape, "to the Mermalair."

Izuku Midoriya, a boy who had spent his entire life obsessing over hero bases, support gear, and agency layouts, was completely speechless. The room before him was a sprawling, subterranean technological marvel that perfectly captured the aesthetic of a retro comic book come to life. 

Massive supercomputers with spinning tape drives and hundreds of flashing, colorful buttons lined the walls. Glass display cases held various costumes, gadgets, and terrifyingly ridiculous weapons. In the center of the room sat a massive, circular console surrounding a glowing holographic globe of Bikini Bottom. Above them, hanging from the cavernous ceiling, was an array of monitors displaying live feeds of the city streets—currently showing the terrified citizens fleeing the downtown area. 

"It's... it's incredible," Izuku breathed, his eyes wide as saucers. He instantly pulled out a spare notebook from his pouch, his pen clicking frantically. "The processing power of those mainframe computers seems outdated by modern surface standards, but the aquatic integration is flawless! The circuitry must be coated in a hydrophobic resin! And those monitors—they're drawing power from a localized geothermal tap! The sheer engineering..."

"Behold, the Wall of Weaponry!" SpongeBob interrupted, gesturing to a massive glass case. 

Izuku practically teleported to the case, his face pressed against the glass. He muttered at lightning speed. "The Aqua-Glove... an early prototype for hydro-kinesis? The Boomerang Fish... aerodynamic and scaly! And that... is that the legendary Orb of Confusion?!"

"Don't look directly at it, Deku!" SpongeBob warned, covering his own eyes. "It'll scramble your brain like a jellyfish egg!"

Izuku immediately looked away, scribbling furiously. "Noted. Psychological warfare support item. Emits localized cognitive-dissonance frequencies." 

SpongeBob marched past the weapons, moving deeper into the armory. "As amazing as the Orb is, we don't need it today. Plankton is already confused enough to think Chum is a good building material. We need something for you. Something to make you fast."

SpongeBob stopped in front of a smaller, dust-covered display case tucked in the corner. He wiped the glass with his spongy hand. Inside sat a pair of boots. They were sleek, silver, and adorned with tiny, aerodynamic fins on the ankles. Next to the boots was a simple, black domino mask made of a rubbery material. 

"Here we are," SpongeBob said, unlatching the case. "The Water-Treader Boots. Worn by Mermaid Man during the great 'Sardine Sprint' of 1974. They were designed to combat villains who used the heavy ocean currents against him."

Izuku slowly took one of the boots from SpongeBob. It was surprisingly light, entirely different from the heavy, iron-soled boots of his Deku costume. He ran his gloved hand over the silver material. 

"How do they work?" Izuku asked, his eyes gleaming with analytical fervor. 

"Hmm," SpongeBob tapped his chin. "Well, if I remember the comic correctly, Mermaid Man said, 'By the power of Neptune, my feet are slippery!'"

Izuku blinked. "Right. But practically speaking..." He flipped the boot over, examining the sole. There were microscopic vents lining the bottom and the sides. "Wait. Are these localized cavitators?"

"I thought they were boots," SpongeBob said helpfully. 

"No, look at the micro-valves!" Izuku's muttering reached a fever pitch. "If these boots draw power from the kinetic energy of the user's steps, they could expel a microscopic, high-pressure layer of air directly around the legs and feet. It creates a super-cavitating bubble! The air acts as a lubricant against the water. It would reduce hydrodynamic drag to practically zero! It's the same principle used in high-speed surface torpedoes!"

Izuku looked at SpongeBob, his face flushed with excitement. "SpongeBob, if these work the way I think they do, the water won't slow me down anymore. I'll be able to move just as fast underwater as I can on land. Maybe even faster, because the buoyancy negates my body weight!"

"That's exactly what we need!" SpongeBob cheered. "Put 'em on, Green Barnacle!"

Izuku quickly unlaced his red iron-soled boots, setting them respectfully on the floor. He slid his feet into the silver Water-Treader boots. They adjusted automatically, shrinking slightly to perfectly fit his feet. 

"Now, for the final touch," SpongeBob said, holding up the black domino mask. His goofy demeanor faded, replaced by a surprising solemnity. "The Green Barnacle needs a proper mask. To hide his civilian identity, and to strike fear into the hearts of those who would steal fast food."

Izuku looked at the mask. His own cowl was torn and hanging loosely around his neck from the battle with the Chum-Nomu. He reached out and took the black mask. 

In the world of heroes, a mask was a symbol. For Izuku, his original mask was meant to mimic All Might’s smile. But this mask... this was different. Barnacle Boy was the sidekick. The grumpy, underappreciated, but fiercely loyal partner to the great Mermaid Man. 

Izuku placed the mask over his eyes. It adhered seamlessly to his skin. 

He didn't feel grumpy. He felt empowered. He felt like he was part of a team. 

"How do I look?" Izuku asked. 

SpongeBob gasped, stars literally forming in his eyes. "You look... F.U.N.! Fierce, Unstoppable, and Nautical! Now, let's test those boots out!"

Izuku nodded. He took a deep breath, letting the familiar warmth of One For All pool in his chest. I won't use five percent. Let's see what happens at eight.

Full Cowling - Eight Percent!

The green lightning erupted around him, crackling with intensity. Izuku dropped into a sprinter's stance. "I'm going to run to the other side of the cavern. Watch my back."

Izuku pushed off. 

The result was instantaneous and explosive. The moment his foot applied pressure, the micro-valves in the boots activated with a high-pitched hiss. A thin, shimmering layer of air encased his legs. 

There was no drag. There was no invisible wall of water holding him back. 

Izuku shot across the Mermalair like a green bullet. The sheer acceleration caught him off guard. He crossed the fifty-yard distance in a fraction of a second, hurtling directly toward a solid rock wall. 

"Ah!" Izuku yelped. He twisted his body mid-air, planting his feet against the wall. The boots hissed again, neutralizing the impact. He used the momentum to rebound, ricocheting off the ceiling, bouncing off the central supercomputer console, and landing perfectly beside SpongeBob, the green lightning slowly fading. 

"Whoa," Izuku breathed, his heart hammering with exhilaration. "The mobility is incredible. I have complete terrestrial movement speed, plus the added benefit of aquatic three-dimensional drifting. SpongeBob, this is perfect. I can generate the heat we need now."

"I knew they’d fit!" SpongeBob cheered. "But wait... heat? How are you going to generate heat just by running fast? Are you going to rub your feet together like a cricket?"

"No," Izuku smiled, his strategic mind locking in on the plan. "When an object moves through water at extreme speeds, it creates immense friction. If I use One For All to push my speed past the water's natural boiling point at localized impact zones... I won't just punch the Chum-Nomu. I will strike it with a hyper-heated, concentrated steam explosion. We'll dry out the chum instantly, shattering its structural integrity."

SpongeBob stared at him blankly for three long seconds. "I have no idea what you just said, but it sounded science-y and painful for Plankton, so I love it! Now, we have the gear, we have the plan, but we have one big problem."

"What's that?"

"The Chum Bucket is all the way across town!" SpongeBob pointed to a monitor showing a map of Bikini Bottom. "And the Chum-Nomu is standing guard! If we run there, we might be too late to save Mr. Krabs. We need a vehicle. We need..."

SpongeBob’s voice dropped to a dramatic whisper. "...The Invisible Boatmobile."

Izuku’s eyes lit up. "An invisible stealth vehicle? That would be perfect for bypassing Plankton's defenses! We could get right up to the doors before he even knows we're there! Where is it?"

"It's right..." SpongeBob spun around, pointing dramatically toward an empty parking space in the corner of the cave. "...there!"

Izuku squinted. He saw a few oil stains on the rock floor, but absolutely nothing else. "Are you sure it's parked there?"

"Positive! I helped Mermaid Man wash it last Tuesday!" SpongeBob marched confidently toward the empty space. "I just need to find the door handle. It's right... oof!"

SpongeBob walked face-first into thin air. His nose flattened with an audible squeak, and he tumbled backward onto the floor. 

"Found it!" SpongeBob gave a thumbs-up. He stood back up, feeling the empty space with his hands. "Okay, here’s the hood... here’s the windshield... ah! The door!" 

Izuku watched in absolute bewilderment as SpongeBob seemed to pull open an invisible door and hop into a seated position, suspended two feet in the air. 

"Hop in, Green Barnacle! Shotgun!" SpongeBob yelled, patting the empty air next to him. 

Izuku hesitantly approached the empty space. He reached out, his gloved hand stopping abruptly as it hit a cool, smooth, hard surface. It felt like fiberglass, but his eyes registered absolutely nothing. He fumbled for a moment, tracing the outline of a door, finding a handle, and pulling it open. He climbed in, sitting down on what felt like a plush, leather bucket seat. 

Optical camouflage? Izuku thought, looking around. He could see his own legs, but the car around him was entirely transparent. No, optical camouflage usually has a slight shimmer or light distortion. This is total light refraction. It’s bending 100% of the visible light spectrum around the chassis. The engineering required to build this is centuries ahead of surface-level support companies!

"Alright, buckle up!" SpongeBob said. A heavy click sounded near Izuku's hip, though he couldn't see the seatbelt pressing against him. "Keys, keys, keys... ah! Good thing Mermaid Man leaves the spare in the invisible visor!"

Izuku heard the jingle of keys, followed by the insertion of a key into an ignition. 

With a roaring, throbbing purr, the Invisible Boatmobile roared to life. Two jets of blue fire erupted from the rear of the empty space, illuminating the back of the car for just a fraction of a second. The vehicle hovered slightly off the ground, humming with immense power. 

"SpongeBob," Izuku asked, a sudden, horrifying realization dawning on him. "Do you... have a driver's license?"

SpongeBob froze. His hands were gripping the invisible steering wheel. He slowly turned his head to look at Izuku. A massive, nervous drop of sweat rolled down his porous forehead. 

"Well," SpongeBob chuckled nervously. "Define 'license'."

"A legal document issued by the government proving you have passed a driving test," Izuku said, gripping the invisible dashboard tightly. 

"Oh! In that case... no," SpongeBob smiled weakly. "I've failed my boating exam one million, two hundred and fifty-eight thousand times. But Mrs. Puff says I'm making progress!"

"SpongeBob, you can't drive this!" Izuku panicked. "It's a high-performance superhero vehicle! We'll crash!"

"Nonsense!" SpongeBob declared, slamming his invisible foot on the invisible gas pedal. "I've watched Mermaid Man do this a hundred times! Away we go!"

The Invisible Boatmobile launched forward with the force of a rocket. 

Izuku was pinned against the invisible seat by the sheer G-force. "SPONGEBOB! THE WALL!" 

"I see it! I see it! Turning, turning, TURNING!" SpongeBob shrieked, wrenching the invisible steering wheel to the left. 

The car drifted violently, the invisible tires screaming against the cave floor. They barely missed a stalagmite, spinning a chaotic 360 degrees before rocketing up the exit tunnel of the Mermalair. 

They burst out of the cave entrance, launching into the open waters of Bikini Bottom. 

"See? Perfect execution!" SpongeBob cheered, right before clipping the edge of a massive brain coral. The car spun wildly out of control, doing barrel rolls through the water. 

"AHHHHHHH!" SpongeBob screamed, covering his eyes with his hands. "I CAN'T LOOK! TAKE THE WHEEL, GREEN BARNACLE! TAKE THE WHEEL!"

"I don't know how to drive!" Izuku screamed back, terror gripping his heart. "I'm only sixteen! I only have my provisional hero license, not a driver's license!"

"JUST DRIVE!" 

Izuku unbuckled his seatbelt, reaching across the console and grabbing the invisible steering wheel. He shoved SpongeBob into the passenger seat and slid behind the wheel. 

The car was hurtling straight toward a residential neighborhood. 

Izuku’s brain went into overdrive. Okay, okay, calm down! It's just a vehicle. It operates on physics. But I can't see the steering wheel, I can't see the dashboard, and I don't know the dimensions of the car! If I can't see where the bumper ends, I can't calculate my turning radius!

They were heading straight for a large, muffler-shaped house. 

Calculate! Izuku thought, his eyes darting frantically. If the seat width is standard, the car is roughly six feet wide. The engine thrust is in the rear, creating a pivot point just behind the driver's seat. If I pull the wheel forty-five degrees to the right...

Izuku yanked the wheel right. 

The car didn't turn fast enough. It clipped a mailbox, sending it spinning into the distance. 

"We're gonna crash!" SpongeBob yelled. 

Izuku gritted his teeth. Math isn't going to work. There are too many unknown variables! I can't rely on my calculations. I have to rely on my Quirk!

Izuku activated One For All at five percent. The green lightning flooded his system, but he didn't channel it into his muscles for strength. He channeled it into his nervous system, heightening his reflexes, his kinetic vision, and his spatial awareness. 

He stopped trying to see the car. He closed his eyes for a split second, feeling it. He felt the vibration of the engine through the invisible floorboards. He felt the resistance of the water pushing against the invisible windshield. He felt the exact center of gravity. 

Izuku opened his eyes. They glowed with an intense emerald light. 

"Hold on, Invincibubble," Izuku said, his voice deadly calm. 

He slammed his foot on the invisible brake, drifting the car smoothly around the corner of Conch Street, narrowly missing Patrick’s rock. He hit the gas again, the blue jets roaring as they sped down the main highway toward downtown Bikini Bottom. 

"Wow!" SpongeBob cheered, watching Izuku navigate the traffic with flawless precision, swerving between boatmobiles without a scratch. "You're a natural, Green Barnacle! Did you learn to drive at U.A. High?"

"No," Izuku said, weaving around a slow-moving kelp-truck. "I'm just using my Quirk to feel the hydrodynamic pressure shifts around the chassis. If I know where the water is breaking, I know where the car ends."

"Fascinating!" SpongeBob pulled out a notebook and began scribbling. "I must tell Mrs. Puff about this 'Quirk' method!"

"I don't think that's a good idea," Izuku muttered. "Just point me toward the Chum Bucket."

"Straight ahead! Downtown is just over the next ridge!" 

While Izuku Midoriya was mastering invisible aquatic vehicular manslaughter evasion, Sheldon J. Plankton was preparing for his ultimate victory. 

Inside the Chum Bucket, the scene was grim. The interior had been completely retrofitted into a horrifying industrial factory. The massive Chum-Nomu stood in the center of the room, completely motionless, guarding a large, glowing contraption. 

Mr. Krabs was tied securely to a chair suspended over a vat of boiling grease. His eyes were wide with fury. "You won't get away with this, Plankton! You can't just steal me formula! It's plagiarism! It's thievery! It's... bad for business!"

"Oh, Eugene, you're missing the big picture!" Plankton gloated, standing on a catwalk above his captive. He was holding the stolen glass bottle containing the Secret Formula. "I'm not just going to make Krabby Patties. I'm going to weaponize them!"

Plankton walked over to a control panel where Karen’s screen was glowing ominously. Next to the panel, the MHA villain, Rift, was slumped on the floor, looking completely drained. The energy cuffs on his wrists were glowing red hot. 

"Explain the genius of my plan, Karen!" Plankton commanded. 

"If you insist, Sheldon," Karen sighed, her robotic voice echoing through the metal chamber. "Sheldon has placed the Secret Formula into the Chum-Transmuter’s core processor. By scanning the molecular structure of the recipe, the machine can mass-produce billions of microscopic, synthetic Krabby Patties."

"Exactly!" Plankton cackled. "But how do I distribute them, you ask? How do I make everyone eat at the Chum Bucket? I don't! I force-feed them!"

Plankton pointed his tiny finger at Rift. "Using this dimensional battery, I have wired the Transmuter to his Quirk! But instead of opening portals to other dimensions, I have calibrated it to open millions of micro-portals directly into the stomachs of every citizen in Bikini Bottom!"

Rift looked up, his face pale. "You're insane. My Quirk isn't meant for that kind of precision. The strain... it'll kill me! And it'll probably rupture their organs!"

"Acceptable casualties in the pursuit of fast-food dominance!" Plankton laughed maniacally. "Once I teleport my patented, mind-control-laced Chum-Patties into their bellies, the entire city will bow to my every whim! I will be king!"

Mr. Krabs gasped. "Mind control?! You're ruining the integrity of a good burger! You're a monster, Plankton!"

"I am a visionary!" Plankton yelled, raising his arms. "And nothing can stop me! The doors are sealed! The Chum-Nomu is indestructible! In exactly five minutes, the machine will hit full power, and Bikini Bottom will be mine!"

"Don't count your sea-chickens before they hatch, Plankton!" 

The voice didn't come from inside the lab. It came from outside, broadcasted through a megaphone. 

Plankton froze. He scurried over to a periscope in the center of the room, pulling it down to look outside. 

Through the lens, Plankton saw the street outside his restaurant. It was empty. But hovering in the water, suspended a few feet off the ground, were two figures. 

SpongeBob SquarePants was sitting in mid-air, holding a megaphone, wearing his purple towel and colander helmet. Next to him, hovering in a seated position with his hands on an invisible steering wheel, was the green-haired boy, now wearing a black domino mask and sleek silver boots. 

"The sponge and the kelp-boy?" Plankton sneered. "How are they floating?"

"Plankton!" SpongeBob’s voice boomed. "We know you're in there! Surrender Mr. Krabs and the formula, and we promise to go easy on you! Otherwise, the Green Barnacle and the Invincibubble are going to come in there and wipe the floor with your Chum-Nomu!"

"You think you can breach my fortress?!" Plankton yelled back through a loudspeaker mounted on the Chum Bucket’s roof. "I've fortified these doors with the stolen technology of a thousand surface-world villains! My automated turrets will blast you into coral dust before you even touch the paint!"

True to his word, hatches along the roof of the Chum Bucket slid open. A dozen automated laser turrets—stolen from U.A.'s entrance exam stockpiles and modified to work underwater—emerged, locking their targeting lasers directly onto the Invisible Boatmobile. 

"He's got artillery!" SpongeBob gasped, dropping the megaphone. "Green Barnacle, what do we do?!"

Izuku analyzed the turrets. Standard U.A. issue. Three-second lock-on delay. The blast doors are reinforced steel, likely five inches thick. But the hinges are rusted from the saltwater environment.

Izuku gripped the invisible steering wheel tighter. The green lightning of One For All flared brilliantly around him, illuminating the interior of the invisible car. 

"We don't dodge," Izuku said, a fierce, determined grin spreading across his face beneath the black mask. "We go right through. SpongeBob, buckle your seatbelt."

"It is buckled!" 

"Then hold on!" 

Izuku slammed his foot on the invisible gas pedal. The twin jets of the Boatmobile roared, blasting them forward at breakneck speed. 

The turrets opened fire. 

Red laser blasts tore through the water, superheating the ocean and creating trails of boiling bubbles. But Izuku was too fast. With One For All enhancing his reflexes, he jerked the steering wheel, making the Invisible Boatmobile barrel roll through the barrage. Lasers harmlessly passed through the space where they had been a millisecond before. 

"He's dodging everything!" Plankton panicked, watching through the periscope. "Fire the heavy cannons!"

Two massive cannons emerged from the sides of the Chum Bucket, firing heavy, concussive energy blasts. 

"Brace for impact!" Izuku yelled. 

He didn't dodge the heavy blast. He drove the Invisible Boatmobile directly into it. The sheer density of the invisible hull absorbed the blast, the kinetic energy violently shaking the car. 

"We're not going to make it!" SpongeBob screamed. 

"Yes, we are!" Izuku roared. "EJECT!" 

Izuku hit the invisible eject button on the console. 

The roof of the Boatmobile blew off. Izuku and SpongeBob were launched out of the car, rocketing toward the Chum Bucket just as the empty Invisible Boatmobile smashed into the heavy steel blast doors. 

The resulting explosion was massive. The invisible car acted like a kinetic missile, buckling the thick steel doors inward and completely shattering the rusted hinges. 

Smoke and bubbles filled the water. The alarm klaxons inside the Chum Bucket wailed loudly. 

Inside, Plankton stumbled backward, coughing as the smoke cleared. The blast doors had been blown wide open, hanging by a thread off their frames. 

Through the smoke, two silhouettes landed gracefully on the metal floor of the Chum Bucket laboratory. 

The green lightning of One For All pierced the gloom. Izuku stood tall, his silver boots gleaming, his green hair wild, the black domino mask hiding his eyes but highlighting his fierce scowl. Next to him, SpongeBob stood with his hands on his hips, his cape billowing in the lingering currents of the explosion, his spatula drawn like a sword. 

They stood shoulder-to-shoulder, striking a flawless, dramatic superhero pose. 

"Halt, evildoer!" SpongeBob announced, his voice ringing with true, heroic authority. "Your recipe for disaster ends here!"

"You're not mass-producing anything today, Plankton," Izuku added, cracking his knuckles. The Water-Treader boots hissed softly beneath him. "I'm going to take down your monster. And then I'm going home."

Plankton stared at the duo, his single eye twitching with rage. He pointed a trembling finger at them. 

"CHUM-NOMU!" Plankton shrieked. "TEAR THEM LIMB FROM LIMB!"

The massive beast roared, stepping out of the shadows, its exposed brain glowing sickly green. It raised its fists, ready to crush the heroes into paste. 

Izuku didn't flinch. He lowered his stance, focusing One For All entirely into his legs. 

Let's see just how fast a Barnacle can move, Izuku thought. 

The final battle for Bikini Bottom had begun.