What if deku ate the castle castle fruit

 

 

The forest bordering the Musutafu residential district was, to a four-year-old, an endless labyrinth of looming shadows and gnarled roots. To Izuku Midoriya, however, it was currently the only viable tactical retreat.

 

His small, red-sneaker-clad feet slammed into the damp earth, kicking up clumps of moss and dead leaves. His lungs burned, pulling in ragged, desperate breaths, but he didn't dare stop. Behind him, echoing through the dense canopy of oak and cedar, came the distinctive, sharp crack-pop! of miniature fireworks.

 

"Get back here, Deku!"

 

The voice belonged to Katsuki Bakugo. Only weeks ago, they had been equals, splashing in the creek and pretending to be All Might. But then Katsuki’s Quirk had manifested. Explosions. A flashy, powerful, heroic Quirk that immediately placed him at the top of the playground hierarchy. Izuku, on the other hand, had yet to show a single sign of a special ability. The extra joint in his pinky toe was a biological death sentence to his dreams, though he hadn't received the official diagnosis yet. The playground had already diagnosed him well enough.

 

Crack-pop!

 

"You can't hide from me, you Quirkless loser!" Katsuki’s voice was closer now, accompanied by the rustling of his two lackeys pushing through the brush.

 

Izuku ducked under a low-hanging branch, a tear streaking through the dirt on his freckled cheeks. His stomach let out a hollow, agonizing rumble. In his haste to avoid Katsuki during the lunch recess, he had skipped his meal entirely. Now, the afternoon sun was dipping below the horizon, casting long, eerie shadows across the forest floor, and Izuku was running on empty.

 

He scrambled up a small embankment, his hands sinking into the damp soil, and slid down the other side, tumbling into a secluded hollow entirely enclosed by thick, thorny bushes. He pressed his back against the rough bark of an old tree, clamping both hands over his mouth to muffle his heavy breathing.

 

Please go away, please go away, he pleaded silently, squeezing his eyes shut.

 

He heard the crunch of boots on the ridge above.

 

"Where did he go?" one of the lackeys asked, panting.

 

"Who cares?" Katsuki spat, the sound of a small explosion emphasizing his annoyance. "If he wants to cry in the woods until it gets dark, let him. He's just a pebble anyway. Come on, I'm hungry."

 

The footsteps gradually receded, fading into the ambient chirp of cicadas and the rustle of the evening wind. Izuku remained frozen for what felt like an eternity, terrified it was a trick. Only when the silence became absolute did he finally lower his hands, letting out a long, shaky exhale.

 

He was safe. But he was also completely lost, and his stomach was knotting itself into painful, hungry cramps.

 

Izuku wiped his eyes with the back of his dirt-smudged sleeve and stood up, looking around the hollow. It was surprisingly peaceful here. The sunlight filtered through the leaves in golden, dusty columns. And right in the center of one of those columns, resting atop a moss-covered stump, was the strangest fruit Izuku had ever seen.

 

It was roughly the size of a honeydew melon, but shaped vaguely like a pineapple, with a thick, rind-like skin. The color was what drew the eye: a pale, sickly greenish-white. But the most unnatural thing about it was the pattern. The entire surface was covered in deep, concentric swirls that seemed to draw the eye inward, spiraling into infinity. A strange, curly stem protruded from the top, twisting like a pig's tail.

 

Izuku approached it cautiously. He had read about all sorts of Quirks, and he knew that some Pro Heroes or Villains could create objects. Had someone left this here? Was it a trap?

 

His stomach let out another violent rumble, practically echoing in the quiet clearing.

 

Izuku swallowed hard. His mother always told him not to eat things he found on the ground, but this was resting cleanly on a stump, almost like it had been served on a platter. And it looked... well, it didn't look appetizing, but it was food.

 

"Just one bite," Izuku whispered to himself, reaching out with trembling hands.

 

The fruit was heavier than it looked, possessing a dense, unyielding weight. Izuku brought it to his lips, closing his eyes, and sank his teeth into the swirled rind.

 

The immediate sensation was one of profound, unspeakable regret.

 

It was, without exaggeration, the single worst thing Izuku had ever tasted. It tasted like ash mixed with sour milk, laced with a metallic tang resembling rusty pennies and battery acid. The texture was fibrous and rubbery, resisting his teeth before suddenly giving way in a burst of foul, bitter juice.

 

Izuku gagged violently. His immediate instinct was to spit it out, to scrub his tongue with dirt to get the flavor out of his mouth. But as he hunched over, coughing and sputtering, an odd warmth bloomed in the back of his throat. Before he could expel the bite, an involuntary spasm forced him to swallow.

 

The chunk of fruit slid down his esophagus like a lead weight.

 

Izuku dropped the rest of the fruit. It hit the moss with a heavy thud, rolling slightly before coming to a stop. He fell to his knees, clutching his stomach, tears streaming down his face from the sheer vileness of the taste.

 

"Gross..." he whimpered, spitting repeatedly into the dirt.

 

But the bad taste was quickly overshadowed by a new, far more alarming sensation.

 

It started in his chest. A deep, mechanical clunk, like a heavy iron deadbolt sliding into place. Izuku gasped, his eyes widening. He pressed his small hands to his sternum. Beneath his flesh, he didn't feel the frantic, rabbit-like fluttering of his four-year-old heart.

 

He felt a slow, rhythmic, tectonic thrum. Like the roaring hearth of a massive furnace.

 

Then came the grinding. It sounded like stone scraping against stone, echoing from within his very bones. Izuku cried out in panic, falling backward onto the grass. He watched in horror as his own stomach seemed to square off, his ribs shifting and expanding with heavy, metallic groans. He felt no pain, only an intense, dizzying pressure, as if his internal organs were being aggressively rearranged by an invisible architect.

 

His vision swam. The trees spun around him in a sickening vortex. He felt incredibly heavy, as if his flesh had been replaced by lead and mortar.

 

"Deku!"

 

The sharp shout cut through the grinding noise in his ears. Izuku blinked, his vision clearing just enough to see Katsuki standing on the edge of the hollow, glaring down at him. The two lackeys flanked him, looking smug.

 

"Thought you could hide down here, huh?" Katsuki sneered, sliding down the embankment. Small sparks danced across his palms. "You look pathetic, crying in the dirt. You really don't have a Quirk, do you?"

 

Izuku tried to speak, to tell Katsuki that something was wrong, that he was sick, but his throat felt stiff, coated in an invisible layer of brick dust.

 

"I-I'm..." Izuku stammered, his voice sounding oddly resonant, echoing as if spoken inside a large, empty hall.

 

Katsuki frowned, taking a step closer. "What's wrong with your voice? Are you making fun of me?"

 

"N-No, Kacchan, please—"

 

"Shut up!" Katsuki raised his right hand, a larger explosion popping in his palm, casting a harsh orange light over the hollow. He lunged forward, closing the distance between them in a split second, aiming a warning blast right at Izuku's chest to scare him.

 

Izuku instinctively crossed his arms over his face and squeezed his eyes shut, bracing for the burning impact.

 

KACHUNK.

 

A sound like dropping a massive steel portcullis echoed through the clearing.

 

Katsuki didn't hit flesh. In fact, he didn't hit anything. He stumbled forward, his momentum carrying him past his target. But strangely, as Katsuki crossed an invisible boundary about ten feet away from Izuku, the world around the blonde boy warped violently.

 

To Izuku, who cautiously peeked through his arms, Katsuki seemed to suddenly shrink. In the blink of an eye, the aggressive, explosive four-year-old was reduced to the size of an action figure.

 

To Katsuki, the world suddenly exploded in size. The blades of grass became towering green monoliths. But he didn't have time to process this, because he was falling forward, straight toward Izuku's chest.

 

Except, Izuku's chest was no longer a chest.

 

From just below his collarbone down to his navel, Izuku's torso had hinged open. A perfectly rectangular flap of skin and muscle had dropped down, suspended by thick, heavy iron chains that materialized from within. It formed a literal drawbridge.

 

Miniature Katsuki screamed as he tumbled through the opening, landing with a soft thump inside Izuku.

 

The two lackeys, still standing on the ridge, stared in absolute, paralyzing horror. One moment, their boss was attacking the Quirkless kid. The next, a heavy mechanical sound echoed out, Katsuki vanished, and a miniature version of him was swallowed by a glowing, stone-walled cavern inside Midoriya's torso.

 

They looked at each other, their faces draining of blood, and then turned and fled into the woods, screaming at the top of their lungs.

 

Izuku was frozen. He looked down at his own chest.

 

It was open. He could see inside himself. But he didn't see blood, or lungs, or ribs.

 

He saw a room.

 

It was a meticulously crafted, miniature foyer. The floor was laid with polished stone tiles. The walls were made of sturdy, gray castle bricks. Tiny, iron-wrought sconces hung on the walls, holding small torches that crackled with warm, real fire. A plush red carpet led from the drawbridge of his skin to a set of heavy wooden double doors at the back of the chamber, which would presumably be where his spine should be.

 

And sitting on the red carpet, rubbing his head, was a two-inch-tall Katsuki Bakugo.

 

"What... what the heck?!" Katsuki's tiny voice floated up from the foyer, high-pitched and squeaky like a cartoon mouse. He stood up, looking around the stone walls, completely bewildered. "Where am I?! Did you eat me, you damn nerd?!"

 

Izuku's brain short-circuited. "K-Kacchan?!" he yelled, staring down into his own chest cavity.

 

Miniature Katsuki looked up, seeing Izuku's massive, terrified face peering down through the open drawbridge like a giant looking through a skylight.

 

"Let me out of here!" Katsuki shrieked, his tiny hands sparking. He slammed his palms against the stone brick walls of Izuku's interior. Pop! Pop!

 

Izuku flinched, expecting agony, but he felt absolutely nothing. The explosions, scaled down to match Katsuki's miniature size, were barely stronger than a firecracker. They left faint scorch marks on the stone bricks, but the walls held firm. Katsuki was trapped in an impenetrable fortress.

 

"Stop! Kacchan, you're gonna hurt yourself!" Izuku cried, his hands hovering frantically over his open chest, unsure of how to help. He didn't want to reach in and accidentally crush his friend.

 

"I'll blow my way out! Die! Die! Die!" Katsuki yelled, unleashing a barrage of miniature explosions against the heavy wooden double doors at the back of the foyer.

 

Izuku began to panic. He stood up, and as he did, the interior of the castle tilted.

 

Katsuki lost his footing on the red carpet, tumbling backward toward the drawbridge. "Whoa! Hey! Keep still, you stupid—"

 

Before Katsuki could finish, he slid down the fleshy drawbridge and tumbled out into the open air. As soon as he crossed the invisible ten-foot radius surrounding Izuku's body, the bizarre physics of the Quirk reversed.

 

Poof.

 

In a fraction of a second, Katsuki expanded back to his normal size, landing hard on his rear end in the dirt. He scrambled backward, his eyes wide with unprecedented terror, staring at Izuku.

 

Izuku stood there, looking equally terrified, his chest still gaping open to reveal the torch-lit stone hallway within.

 

"You're a monster!" Katsuki screamed, his usual bravado completely shattered. He scrambled to his feet, ignoring the dirt on his shorts, and bolted into the woods, running faster than he ever had in his life.

 

Izuku was left alone in the hollow. He looked down at his chest. With a trembling finger, he touched the edge of the drawbridge.

 

Clack.

 

As if commanded by his subconscious, the heavy iron chains began to retract. The rectangular flap of flesh and clothing pulled upward, slotting perfectly back into his chest. A heavy, unseen deadbolt slid into place with a resounding clunk.

 

Izuku patted his chest. It felt solid. Harder than before, perhaps, but it was closed. He looked at the stump where the fruit had been. The half-eaten, swirled melon was gone, as if it had evaporated into thin air the moment he swallowed its flesh.

 

The silence of the woods felt heavier now. Izuku didn't know what had just happened, but one thing was abundantly clear: he wasn't Quirkless anymore.

 

 

 

Two Days Later - Musutafu General Hospital

 

Inko Midoriya wrung a tissue between her hands, tearing it to shreds with her anxious fidgeting. She sat in a sterile, white consultation room, her eyes darting between the closed door and her son, who sat on the examination table kicking his feet.

 

Izuku seemed perfectly normal on the outside. He had his messy green hair, his oversized All Might t-shirt, and his bright, inquisitive eyes. But every time he breathed, Inko swore she could hear a faint, metallic clicking, like the gears of a distant grandfather clock.

 

The door opened, and Dr. Tsubasa, a stout man with a bushy mustache and round spectacles, walked in. He was carrying a thick manila folder and a tablet. He looked bewildered, taking off his glasses to rub the bridge of his nose before looking at Izuku, then at Inko.

 

"Mrs. Midoriya," the doctor began, his voice lacking its usual confident cadence. "I... apologize for the delay. We had to run the X-rays and MRI scans three times just to be absolutely certain our equipment wasn't malfunctioning."

 

Inko stood up quickly, her heart in her throat. "Is he okay? Is it a disease? He said his chest opened up, Dr. Tsubasa, I was terrified!"

 

"Please, have a seat," Dr. Tsubasa urged gently. He tapped a button on his tablet, casting the medical images onto the large monitor mounted on the wall. "Your son is not diseased, Mrs. Midoriya. In fact, medically speaking, his vital signs are incredibly strong. However, his anatomy... well. See for yourself."

 

The monitor displayed Izuku's torso. Inko gasped, clapping a hand over her mouth.

 

Where there should have been a heart, lungs, a stomach, and a ribcage, there was instead a sprawling, complex architectural blueprint. The scan showed miniature rooms, hallways, a courtyard, and heavy, thick walls made of an unidentifiable, incredibly dense material. At the center, where his heart should be, a glowing, thermal mass pulsed rhythmically.

 

"What... what is that?" Inko whispered, tears welling in her eyes. "Where are his organs?"

 

"That is the fascinating part," Dr. Tsubasa said, zooming in on the image. "His biological functions have seamlessly integrated with this... structure. That central thermal mass operates as a heart and a furnace. We detected air circulation systems that act as lungs, drawing oxygen through microscopic vents in his skin. His digestive system appears to be some sort of internal incinerator or compost unit. Izuku is, for all intents and purposes, a living building."

 

Izuku looked at the screen, his eyes wide with awe rather than fear. "A building? Like a castle?"

 

"Precisely like a castle, young man," the doctor said, managing a small smile. "Based on the incident you described with young Katsuki Bakugo, we are classifying this as an extremely rare Mutation and Emitter hybrid Quirk. I've taken the liberty of proposing a tentative name for the registry: Living Castle."

 

Inko pulled Izuku into a tight hug, burying her face in his hair. "Oh, Izuku. My brave boy. You have a Quirk."

 

Izuku hugged her back, feeling the solid, unyielding strength of his new body. He didn't feel soft anymore. He felt like a bunker.

 

"How does it work?" Izuku asked, his analytical mind already spinning. "How did Kacchan get so small?"

 

Dr. Tsubasa pulled up a diagram on the tablet. "From what we can gather, your body acts as a pocket dimension. You project an invisible field—an 'absolute threshold'—that extends approximately ten feet around you. Anything that crosses this threshold with the intent to enter your body, or anything you pull inside, is subjected to localized spatial compression. They shrink."

 

"So I can put things inside me?" Izuku asked, fascinated.

 

"In theory, yes. Objects, animals, even people. As long as they remain inside your designated internal 'rooms', they will stay miniature. Once they leave your threshold, they revert to their normal size and mass. It is a staggering manipulation of physics." The doctor looked deeply troubled for a moment. "Mrs. Midoriya, I must warn you. A Quirk of this magnitude, one that alters reality and spatial dimensions, is incredibly rare. Izuku will need careful monitoring. If he ingests something dangerous, or if someone dangerous gets inside him..."

 

"I'll protect him," Inko said fiercely, her maternal instincts flaring. "No one is going to hurt my son."

 

"I can protect myself, Mom!" Izuku said, puffing out his chest. Clink. A small, metal portcullis sound echoed from his sternum. He beamed. "I have a castle! I can be a hero!"

 

Dr. Tsubasa smiled, but it didn't quite reach his eyes. "You have a remarkable defensive Quirk, Izuku. But remember, a castle is only as strong as the stone it's built from. You must take good care of yourself."

 

As they walked home from the hospital that evening, Izuku held his mother's hand. He felt different. The world seemed less frightening. The shadows in the alleys didn't scare him as much, because he knew that beneath his oversized t-shirt, he was made of stone and iron.

 

 

 

Three Months Later

 

The novelty of the "Castle Quirk" had worn off in the neighborhood, replaced quickly by alienation.

 

Izuku found himself isolated on the playground. Katsuki refused to come anywhere near him. The explosive blonde would glare at Izuku from across the sandbox, but the memory of being trapped inside Izuku's chest, powerless and miniature, had deeply unsettled him. Katsuki's pride couldn't handle a target he couldn't break, so he opted to pretend Izuku didn't exist.

 

The other children followed Katsuki's lead. Furthermore, playing with Izuku had become logistically difficult. He was incredibly heavy now. When he hopped on a seesaw, the other child was launched into the air. When they played tag, Izuku's heavy, clanking footsteps made him slow, but if anyone managed to tag him, they bruised their fingers against his hardened skin.

 

He was a fortress. And fortresses were meant to stand alone.

 

One rainy afternoon, Izuku sat in his bedroom. The computer monitor bathed his face in a flickering, pale glow. He was watching the video. The video. The debut of All Might.

 

On the screen, the towering blonde hero carried civilians through a ruined cityscape, laughing booming, triumphant laughs as he stepped over crushed cars and shattered pavement.

 

"Fear not, citizens! Hope has arrived! Because I am here!"

 

Izuku had watched this video thousands of times. Usually, he watched All Might's fists. He watched the way the Symbol of Peace smashed through obstacles, defeated villains with a single punch, and stood victorious as the ultimate deterrent to evil.

 

But today, Izuku watched differently.

 

His eyes drifted away from All Might's blinding smile. He looked at the background. He saw the buildings collapsing. He saw the dust clouds suffocating the streets. He saw the terrified expressions of the civilians huddled in the rubble, completely exposed to the elements and the collateral damage of the battle.

 

All Might was incredible. He could punch a villain into orbit. But he couldn't stop the debris from falling. He couldn't un-crush a house. He was a sword, swinging brightly in the dark.

 

Izuku looked down at his own hands. He balled them into fists. They felt heavy, but when he threw a practice punch at the air, it was slow. His joints locked and ground against each other. He was dense. He was immovable. He was not a sword.

 

Click.

 

Izuku willed his chest to open. The heavy iron chains rattled, and his sternum dropped down like a drawbridge, resting against his stomach. He looked down into his own personal foyer.

 

He had been experimenting over the last few months. His internal space was vast, far bigger than his small body should allow. There were hallways he hadn't fully explored, spiral staircases leading to empty guard towers in his shoulders, and deep, echoing chambers in his legs.

 

More importantly, he discovered he could control the interior. If he focused, he could move the stone walls, open internal trapdoors, and lock rooms tight. He had spent his allowance on small pieces of scrap metal, springs, and marbles, swallowing them and storing them in an armory he had designated near his left lung.

 

He couldn't punch like All Might. He would never be fast enough to dart across a battlefield and snatch fifty people out of the way of an explosion in the blink of an eye.

 

"But I don't have to be fast," Izuku whispered to the empty room.

 

He reached over to his desk and grabbed a brand-new notebook. Its cover was blank. He usually bought notebooks with heroes on the cover, but this one was a simple, sturdy gray.

 

He clicked his pen.

 

He didn't draw All Might. He didn't draw flashy finishing moves or analyze speed Quirks.

 

He drew a wall.

 

If I can't run to save them, Izuku thought, his pen scratching furiously against the paper, I'll bring them inside.

 

He sketched the interior of his chest cavity. He began detailing how he could modify the foyer to be more comfortable. He needed seating. He needed medical supplies. If a villain attacked the city and civilians were trapped, Izuku wouldn't fight the villain. He would run to the civilians, open his drawbridge, and take them all inside.

 

He would become the safe zone.

 

As he drew, a new sensation rippled through him. A strange, dual awareness. He felt his physical body sitting in the chair in his bedroom, but simultaneously, he felt a presence inside his own chest foyer.

 

Izuku gasped, looking down.

 

Standing on the red carpet of his internal hallway was a tiny, translucent green figure. It looked exactly like him, down to the freckles, but made of a shimmering, ghostly energy.

 

"Whoa," Izuku breathed out loud.

 

Inside the chest cavity, the miniature green avatar looked up, meeting the gaze of the giant Izuku peering through the drawbridge. The tiny avatar waved.

 

Izuku waved his physical hand. The avatar mimicked it perfectly, but Izuku realized he didn't have to mimic it. By concentrating, he could move the avatar independently. He made the tiny ghost walk over to a wall and touch a sconce. He felt the cold iron of the sconce through the avatar's fingers.

 

He had an internal manager. An avatar that could interact with anything or anyone he brought inside his castle.

 

Izuku's mind exploded with possibilities. The notebook filled up with ink at a blistering pace.

 

Hero Analysis for the Future was crossed out.

 

In bold, block letters, Izuku wrote the new title:

VANGUARD BLUEPRINTS: THE LIVING FORTRESS.

 

He turned the page. He began drawing schematics for cannons. If he hoarded enough metal pipes, gunpowder, and springs, could he build artillery inside his arms? If he opened small windows on his knuckles, could his internal avatar load the cannons and fire miniature projectiles that would expand to full size the moment they left his threshold?

 

He wasn't just a castle. He could be a tank. He could be a siege weapon.

 

His mother opened the door to his bedroom, carrying a plate of sliced apples. She paused, looking at her son. Izuku was sitting in his chair, his chest wide open, intensely scribbling in a notebook while a tiny, glowing green version of himself was pacing back and forth inside his hollowed-out torso, seemingly organizing invisible boxes.

 

"Izuku, dear?" Inko asked gently, setting the plate down. "Are you... okay?"

 

Izuku looked up. His eyes were burning with a fierce, unwavering determination that Inko had never seen before. The innocent, fragile boy who used to cry at loud noises was gone, replaced by something grounded, heavy, and unbreakable.

 

"I'm fine, Mom," Izuku said, closing his drawbridge with a satisfying clack that shook the floorboards. He smiled, and it wasn't the manic, high-strung smile of All Might. It was a calm, sturdy smile. "I'm just drawing up some renovations. I have a lot of work to do."

 

Inko smiled warmly, brushing his messy hair out of his eyes. "Well, don't work too late. Castles need their sleep too."

 

As she left the room, Izuku looked back at the screen. All Might was still laughing, standing triumphantly amidst the ruin.

 

You can be the sword, All Might, Izuku thought, his small hands resting flat on the sturdy gray notebook. You can smash the villains. But when the sky falls, I'll be the shield that catches it.

 

He picked up his pen and began designing an internal combustion engine to replace his calves. If he was going to be a fortress, he needed to learn how to move like one. The Quirkless boy who ran from explosions was dead. The Bastion of Musutafu was under construction.

 

 

 

Four Years Later - Age 8

 

The construction never stopped.

 

Izuku grew, and as he grew, his internal space expanded exponentially. His body required a massive intake of calories and raw materials to sustain the architectural growth. He didn't eat normal food anymore. Well, he did, but only for the taste. His actual sustenance came from eating iron, limestone, wood, and mortar.

 

He had become a fixture at the local junkyard. The owner, an old man with a Quirk that let him see the chemical makeup of metals, found the boy endlessly amusing. Izuku would show up every Saturday with a wagon, dragging away scrap steel, rusted pipes, and old car engines.

 

"What's a kid like you need with all this junk?" the old man asked one rainy afternoon, watching Izuku load a massive, rusted steel beam onto his wagon.

 

"Upgrades," Izuku said simply.

 

He was eight years old, but he was built like a small tank. His skin had a slight gray tint to it, and his freckles looked like rivets. When he walked, his footsteps cracked the pavement if he wasn't careful.

 

He dragged the wagon to a secluded part of the beach—Takoba Municipal Beach, a place infamous for its illegal dumping. It was a mountain of trash, a monument to society's waste. To Izuku, it was an all-you-can-eat buffet and a hardware store combined.

 

He stood before a pile of discarded washing machines and rusted car doors. He took a deep breath, grounding his stance.

 

Click. Clunk. Rrrrrrumbble.

 

His chest opened, the drawbridge lowering heavily. But it wasn't just his chest anymore. Two square doors opened on his forearms. A small portcullis raised on his stomach.

 

Izuku willed his internal avatar to work. Inside his body, the miniature green clone scurried around a massive, industrial forge he had constructed near his stomach cavity. The avatar grabbed a bundle of scrap metal they had ingested the week before, loading it into a heavy, spring-loaded cannon barrel built into the architecture of Izuku's right arm.

 

Izuku aimed his right arm at a towering pile of broken refrigerators fifty yards away.

 

Fire.

 

Inside, the avatar yanked a lever. A heavy spring snapped forward.

 

A tiny, marble-sized ball of compressed scrap metal shot out of the square window on Izuku's forearm. The moment it crossed the ten-foot threshold of his Quirk, the physics violently corrected themselves.

 

The marble expanded instantly into a massive, jagged sphere of rusted steel the size of a beach ball, retaining all of its miniature velocity but gaining massive weight.

 

BOOM!

 

The steel ball slammed into the pile of refrigerators with the force of a wrecking ball, obliterating them into twisted shrapnel and sending a shockwave across the sandy beach. The sound echoed like a cannon shot over the ocean.

 

Izuku lowered his arm, smoke curling from the open port in his skin. He smiled, a slow, satisfied grin.

 

His artillery was working.

 

He walked over to the wagon he had dragged from the junkyard. He picked up the heavy steel beam. It weighed easily a hundred pounds, but Izuku lifted it with ease. He held it up to his open chest cavity.

 

As the beam crossed the threshold, it shrank, becoming no larger than a toothpick. Izuku dropped it inside. His internal avatar caught it, carrying it off to reinforce a load-bearing wall in the western wing of his ribcage.

 

"Hey! What are you doing out here, kid?!"

 

Izuku snapped his chest shut, the mechanical locks sealing seamlessly. He turned around to see a local police officer walking down the stairs to the beach, shining a flashlight through the gloom.

 

"Just cleaning up the beach, sir!" Izuku called back, his voice deep and resonant.

 

The officer raised an eyebrow, looking at the massive crater of destroyed refrigerators, then at the small, sturdy boy with green hair. "Cleaning? Looks like a bomb went off down here."

 

"Must have been a villain," Izuku lied smoothly, his innocent face giving nothing away. "I just got here. I was going to collect some scrap."

 

The officer sighed, rubbing his neck. "Well, go home. It's getting dark, and this beach isn't safe. Too much unstable trash."

 

"Yes, sir," Izuku said, bowing politely.

 

He grabbed the handle of his empty wagon and began the walk home. He wasn't bothered by the interruption. He had successfully tested his primary cannons, and he had secured enough steel to reinforce his lower levels.

 

Tomorrow, he would begin studying hydraulics. If he was going to turn his legs into treads for all-terrain movement, he needed a better understanding of fluid dynamics.

 

He passed by a television glowing in an electronics store window. The news was on. A villain with a gigantification Quirk was rampaging in a nearby city. The heroes on the screen—Kamui Woods, Backdraft—were struggling to contain the damage. Buildings were crumbling. Civilians were running in terror.

 

Izuku stopped, watching the screen. He watched a piece of a skyscraper detach and plummet toward a crowd of screaming onlookers. The screen cut away before the impact, switching to an anchor warning people to evacuate.

 

Izuku's hands tightened on the handle of his wagon. The metal groaned in protest.

 

He didn't feel fear. He felt a deep, structural imperative.

 

I need to be bigger, he thought, his eyes locked on the destroyed buildings. I need thicker walls. I need more space.

 

He turned away from the screen and continued his walk home. He had ten years before the U.A. High School entrance exams. Ten years to stockpile, design, and build. Ten years to turn a little boy into an impenetrable fortress.

 

The villains of the world were obsessed with destruction. They sought Quirks that could tear down society, burn cities, and break heroes. They wanted to be unstoppable forces.

 

Let them be unstoppable forces, Izuku thought, his heavy footsteps echoing in the quiet street.

 

He would be the immovable object.

 

 

The sea breeze rolling off the coast of Musutafu used to carry the scent of salt, seaweed, and rotting garbage. For years, Takoba Municipal Beach had been a monument to societal apathy, a sprawling wasteland of discarded appliances, rusted car frames, and shattered furniture.

 

By the time Izuku Midoriya was fourteen years old, the breeze smelled only of the sea.

 

The beach was pristine. The golden sand stretched uninterrupted toward the sparkling horizon, catching the pale light of the early morning sun. To anyone else, it would seem a massive community effort had cleared the millions of pounds of illegal dumping.

 

In truth, it was the work of a single, ravenous boy.

 

Izuku stood at the edge of the water, the gentle surf washing over his heavy, steel-toed boots. He didn't look like a typical middle schooler. He was average in height, perhaps even a bit short, but his dimensions were entirely unnatural. His shoulders were broad, his chest barrel-thick, and his posture rigidly upright, as if his spine were made of reinforced concrete. Which, structurally speaking, wasn't far from the truth.

 

Underneath his plain white t-shirt, his skin held a faint, grayish pallor, smooth but completely unyielding. He weighed just over four hundred and fifty pounds.

 

Izuku took a deep breath. Instead of the soft whoosh of air entering biological lungs, his inhalation sounded like the powerful, whirring draw of an industrial ventilation shaft. Deep within his chest, the rhythmic, tectonic thrum of his furnace-heart beat a slow, steady tempo.

 

He bent down, picking up the final piece of trash on the beach: a rusted, jagged sprocket from a long-dead tractor. He examined it, wiping away a clump of wet sand.

 

Click. Clunk.

 

With a sound like a bank vault unlocking, a square hatch on Izuku's right forearm slid open, revealing a dark, stone-lined chute within. He dropped the heavy sprocket inside. It vanished into the darkness, shrinking instantly as it crossed the threshold of his Quirk's localized spatial compression field. The hatch slid shut with a sharp hiss.

 

Inside his body, deep within the sprawling, torch-lit cavern of his central armory, Izuku’s internal avatar—a glowing, translucent green miniature of himself—caught the sprocket as it tumbled out of a chute. The avatar tossed it onto a towering pile of similarly shrunken scrap metal: crushed engines, iron pipes, ball bearings, and coils of copper wire.

 

For ten months, Izuku had used the beach not as a training ground for his muscles, but as a buffet and a hardware store. He had systematically ingested thousands of tons of metal. Through intense concentration and the tireless work of his internal avatar, he had forged that trash into something magnificent.

 

His interior was no longer just a castle foyer. It was a fortified military garrison.

 

The avatar wiped imaginary sweat from its glowing green brow and walked over to a massive, stone-forged blast furnace located near Izuku's stomach cavity. Pushing a heavy iron lever, the avatar fed a scoop of scrap metal into the roaring flames. The furnace didn't burn wood or coal; it burned calories and raw metabolic energy, melting down the rusted trash and purifying it into high-grade steel.

 

Once the steel was molten, the avatar would pour it into molds, forging dense, spherical cannonballs, heavy reinforced plating to thicken Izuku's outer skin, and complex clockwork gears.

 

Izuku opened his eyes, the physical world snapping back into focus. He clenched his right fist. He could feel the heavy, spring-loaded artillery mechanisms locking into place beneath the skin of his forearm. He was fully stocked. He was fully reinforced.

 

"Hey, kid."

 

Izuku turned slowly. The sand crunched heavily under his boots. Standing a few yards away, leaning against the railing of the boardwalk, was a skeletal, blonde man in an oversized white t-shirt and baggy cargo pants. The man was coughing into a handkerchief, looking at Izuku with a mixture of profound bewilderment and deep respect.

 

It was Toshinori Yagi. All Might, in his true, crippled form.

 

Toshinori had been watching the beach for months. He had initially come here looking for a vessel for One For All, hoping the daunting task of cleaning the beach might attract a youth with a heroic, self-sacrificing heart. He had found Izuku. He had watched this strange, heavy boy systematically eat mountains of trash. Toshinori had quickly realized that One For All would likely kill the boy, or perhaps the boy's bizarre biology would outright reject it, treating the Quirk like an invasive architectural flaw.

 

But Toshinori hadn't left. He was fascinated.

 

"You did it," Toshinori said, waving a bony hand at the pristine coastline. "I've been taking my morning walks here for nearly a year. I never thought one kid could eat a whole dump."

 

"Good morning, Yagi-san," Izuku replied politely, bowing at a perfect forty-five-degree angle. His joints let out a soft, well-oiled whir. "The iron content in the older vehicle models was particularly useful for my lower-level fortifications."

 

Toshinori sweatdropped, a nervous smile twitching on his gaunt face. He still didn't entirely understand how the boy's Quirk worked, and quite frankly, it terrified him just a little bit. "Right. Fortifications. You're heading to the U.A. Entrance Exam today, aren't you? Aldera Junior High uniform under that jacket?"

 

"Yes, sir. I have to go home and change into my tailored uniform." Izuku looked out at the ocean. "I'm not fast, Yagi-san. And I'm not agile. But I'm going to pass."

 

Toshinori looked at the boy's eyes. There was no hesitation. No anxious fluttering. Only the cold, hard certainty of a stone wall.

 

"I believe you will, young Midoriya," Toshinori said softly. "A hero isn't always the one who strikes the fastest blow. Sometimes, a hero is the shield that refuses to break. Give 'em hell today."

 

Izuku nodded, a small smile cracking his stoic face. "I will."

 

 

 

Two hours later, Izuku stood before the towering, imposing gates of U.A. High School.

 

The courtyard was bustling with hundreds of prospective students, all buzzing with nervous energy, comparing Quirks, and stretching. Izuku stood entirely still. He wore a custom-tailored middle school uniform; his mother had spent hours taking out the seams and reinforcing the fabric with heavy canvas to accommodate his unnatural width and the sharp, blocky edges of his shoulders.

 

He didn't need to stretch. He needed to calibrate.

 

Internally, his avatar was sprinting through the stone corridors of his chest, double-checking the locks on the heavy iron doors that separated his armory from his "Safe Rooms"—plush, velvet-lined chambers he had constructed specifically to house civilians. He checked the tension on the massive coil springs in his forearms. Everything was green.

 

"Stupid Deku."

 

The voice was like sandpaper grating against glass.

 

Izuku didn't flinch. He slowly turned his head. Katsuki Bakugo was stalking up the walkway, his hands shoved deep into his pockets, his crimson eyes glaring daggers at Izuku.

 

Ever since the incident in the woods ten years ago, Bakugo had kept his distance. He had bullied other kids, sure, but he never laid a finger on Izuku. It wasn't out of kindness. It was out of a deep, suppressed phobia. The memory of being shrunk down, trapped inside the claustrophobic, impenetrable stone dungeon of Izuku's chest, haunted Bakugo's nightmares. He hated Izuku because Izuku made him feel small. Literally and metaphorically.

 

"Kacchan," Izuku acknowledged, his voice echoing slightly in his chest.

 

"Don't stand in my way, you freak," Bakugo sneered, giving Izuku a wide berth as he walked past. "You think being a walking brick wall makes you a hero? They're gonna test our combat skills today. You can't even touch your own toes. You're gonna fail."

 

Izuku watched Bakugo march toward the auditorium. He didn't feel anger. He simply registered the data. Bakugo was volatile. Explosive. High damage output.

 

If he gets trapped under rubble, Izuku's analytical mind supplied, I'll need to use the reinforced titanium cell in my left quadrant to house him. He'll try to blow his way out out of panic.

 

As Izuku took a step forward, a girl with a brown bob and permanent blush stickers on her cheeks suddenly tripped over an uneven paving stone. She pitched forward, crying out in alarm, destined for a nasty face-plant.

 

Izuku didn't think. His heavy legs moved with startling, piston-like precision. He stepped into her path and caught her by the shoulders.

 

Thud.

 

The girl gasped as she collided with him. It was like running face-first into a bank vault. She bounced back slightly, but Izuku's large, calloused hands held her steady.

 

"Are you unharmed?" Izuku asked, his deep, resonant voice rumbling through his chest.

 

Ochaco Uraraka blinked, rubbing her nose. She looked up at the boy who had caught her. He felt... weird. Solid didn't even begin to cover it. She swore she could hear a faint ticking noise coming from inside him, like a grandfather clock.

 

"Oh! Um, yes! Thank you so much!" she stammered, stepping back. "I was trying to stop myself with my Quirk, but I panicked! Sorry for bumping into you, you're just... wow, you're really sturdy!"

 

"Thank you. It is a structural requirement of my Quirk," Izuku said, giving a slight, rigid bow. "Good luck on your exam."

 

He turned and continued his march toward the auditorium, walking with the heavy, rhythmic cadence of a marching army.

 

Ochaco stared after him, tilting her head. "Structural requirement? What does that even mean?"

 

 

 

The written exam was trivial. Izuku's brain, protected by a skull thicker than a tank's armor plating, processed information with cold, architectural efficiency.

 

The orientation, however, was where the reality of the trial set in.

 

Present Mic, the Voice Hero, stood at the podium in the massive, darkened auditorium, shouting with enough volume to rattle the seats. Izuku sat in the middle row, his hands resting on his knees. Next to him, Bakugo slouched in his chair, scowling.

 

"FOR THE PRACTICAL EXAM, YOU'LL BE CONDUCTING A TEN-MINUTE URBAN BATTLE IN OUR REPLICA CITY DISTRICTS!" Present Mic roared, striking a pose. "YOU'LL BE FACING THREE TYPES OF FAUX VILLAINS, EACH WORTH DIFFERENT POINTS! USE YOUR QUIRKS TO DISABLE THEM AND RACK UP THAT SCORE!"

 

Izuku’s eyes scanned the pamphlet on his desk. Three robots. One-pointer, two-pointer, three-pointer. It was a simple siege scenario.

 

Click. Whir. Ratchet.

 

The silence of the auditorium was punctuated by the soft, mechanical adjustments happening inside Izuku’s body. His internal avatar was preemptively loading the forearm cannons, rolling miniature, cannonball-sized spheres of solid steel into the firing chambers.

 

"Excuse me!"

 

A tall boy with glasses and a severe haircut stood up abruptly several rows ahead, pointing rigidly at the stage. "The printout mentions four types of villains! If this is a misprint, U.A., the most prominent school in Japan, should be ashamed!"

 

The boy then pivoted flawlessly, pointing directly at Izuku. "And you! In the middle row! You've been making a distracting clicking and grinding noise this entire time! If you are unable to control your Quirk and sit quietly, then you should leave! You are distracting the rest of us!"

 

The auditorium fell dead silent. Hundreds of eyes snapped to Izuku.

 

Bakugo, to his credit, leaned away from Izuku, looking at the boy with glasses as if he were suicidal.

 

Izuku stared at the boy with glasses. He didn't blush. He didn't stutter. He simply analyzed the situation.

 

"I apologize for the ambient noise," Izuku said, his voice easily carrying across the massive room due to the natural acoustics of his internal stone chambers. "I am currently loading my internal artillery and calibrating my hydraulic systems for the practical exam. I will engage my sound-dampening panels immediately."

 

Inside Izuku, the green avatar ran over to a wall and pulled a lever. Thick, iron-wrought shutters slammed down over the internal acoustic vents.

 

The clicking and grinding sounds instantly vanished, replaced by total silence.

 

Izuku looked back at the boy with glasses. "Is that preferable?"

 

The boy with glasses blinked, his arm slowly dropping. "Ah. Yes. Thank you for your cooperation." He sat down abruptly, deeply unsettled by the deadpan, emotionless delivery.

 

Present Mic cleared his throat, sweatdropping slightly. "RIGHT! WELL! As Examinee 7111 pointed out, there is a fourth robot! The Zero Pointer! It's a massive obstacle. My advice? Run away from it! Now, GO BEYOND! PLUS ULTRA!"

 

 

 

Test Area B - The Gates

 

The replica city was massive, a sprawling concrete jungle of skyscrapers, alleyways, and wide boulevards. Dozens of examinees stood before the towering metal gates, stretching, hyping themselves up, and eyeing the competition.

 

Ochaco Uraraka stood near the back, taking deep breaths. She saw the sturdy boy from earlier—the one who had caught her. He was standing completely still at the very front of the pack, his eyes locked on the gates.

 

"Okay, start!"

 

Present Mic's voice boomed from the watchtower. The examinees froze, waiting for a countdown.

 

Izuku did not wait.

 

The moment the word 'start' echoed, Izuku's body moved. He didn't sprint like a runner. He charged like a battering ram.

 

His heavy boots slammed into the pavement, cracking the asphalt with every step. BOOM. BOOM. BOOM. He cleared the gates before anyone else had even twitched.

 

"What are you waiting for?!" Present Mic yelled. "There are no countdowns in real battles! Look at the big kid go!"

 

The rest of the students scrambled, pouring through the gates like a panicked herd. But by the time they entered the main boulevard, Izuku was already at work.

 

A group of three One-Pointers and two Two-Pointers rolled out of a side street, their red optical sensors locking onto Izuku. "TARGET ACQUIRED."

 

Izuku didn't break his stride. He planted his left foot, halting his massive momentum instantly. He raised both arms, pointing his fists at the robots.

 

Clank-clank-clank.

 

Square hatches on the tops of his forearms snapped open.

 

Inside his body, the internal avatar screamed a silent battle cry, ripping the firing cords on the twin arm-cannons.

 

THOOM! THOOM!

 

The recoil shuddered through Izuku's heavy frame, but he didn't budge an inch. Two miniature spheres of solid steel, no larger than peas, shot out of his arm ports at Mach 2.

 

The instant they crossed the invisible ten-foot radius surrounding Izuku's body, the spatial compression broke. The pea-sized spheres violently expanded to their true size: heavy, jagged boulders of pure, condensed scrap iron, each the size of a microwave.

 

Because they expanded while maintaining their miniature velocity, the kinetic energy output was apocalyptic.

 

The first iron boulder slammed into a Two-Pointer's chest, tearing through its armor plating like wet tissue paper and out its back, obliterating its internal engine. The second boulder hit a One-Pointer in the head, entirely decapitating it before ricocheting into the wall of a fake building, burying itself three feet deep into the concrete.

 

Izuku didn't pause to admire his work. His internal avatar was already throwing the levers to reload.

 

"Three points," Izuku muttered, his arms dropping as the ruined robots exploded into showers of sparks.

 

The other examinees arriving on the scene stopped dead in their tracks, their jaws dropping.

 

"What... what was that?!" the boy with glasses, Tenya Iida, gasped, watching the smoke curl from the open ports on Izuku's arms.

 

"Don't just stand there!" Izuku shouted back at them, his voice rumbling like thunder. "The objective is point accumulation! Disperse!"

 

With that, Izuku turned and marched down the street, transforming into a one-man blitzkrieg.

 

 

 

Observation Room

 

High above the arena, behind reinforced glass, the faculty of U.A. High School watched the monitors.

 

"We have a strong crop this year," Midnight, the R-Rated Hero, purred, watching a blonde boy shoot lasers from his navel. "Lots of flashy Quirks."

 

"Flashy doesn't mean effective," Aizawa Shota muttered from his sleeping bag in the corner.

 

"Look at this one in Area B," Snipe pointed a gloved finger at a large central monitor. "Examinee Midoriya. He's a walking artillery battery."

 

On the screen, Izuku was walking calmly down a main street. A massive Three-Pointer ambushed him from an alley, swinging a massive metal pincer directly at his head.

 

Izuku didn't dodge. He simply turned his head, letting the pincer strike his cheek.

 

CLANG.

 

A sound like a sledgehammer striking an anvil echoed through the speakers. The robot's pincer actually crumpled. Izuku didn't even flinch. He raised his right hand, placed his palm flat against the robot's chassis, and a port on his chest opened. A barrage of high-velocity iron spikes fired point-blank, shredding the robot's interior.

 

"Incredible," Principal Nezu murmured, sipping his tea. "A Mutation Quirk granting extreme physical density, coupled with an Emitter Quirk that manipulates spatial dimensions. He’s taking raw material, miniaturizing it, storing it, and firing it. He's utilizing the conservation of momentum perfectly upon expansion."

 

"He's got sixty-five points already," Power Loader said, typing frantically on his keyboard. "And he hasn't taken a single scratch. He's just tanking the hits."

 

"Let's see how he handles the real test," Nezu said, his paw hovering over a large red button on his console. "A hero isn't just a weapon. Let's see his spirit."

 

Nezu pressed the button.

 

 

 

Test Area B

 

Izuku was standing in the center of a plaza, currently at seventy-two points. His internal avatar was sweating, shoveling coal into the furnace to keep his energy levels up. Izuku felt a dull ache in his joints from the repeated recoil, but his structure was sound.

 

Suddenly, the ground beneath his feet heaved violently.

 

A shadow fell over the entire plaza. Izuku looked up.

 

At the end of the street, the buildings were being pushed aside like cardboard boxes. A colossal machine, easily the height of a skyscraper, rolled into view on massive treads. Its red eye glowed with menacing intensity. The Zero Pointer.

 

"RUN!" a student screamed.

 

Panic erupted. The examinees, who had been confidently destroying the smaller robots moments ago, broke and fled in absolute terror. The sheer scale of the Zero Pointer was paralyzing.

 

Izuku stood his ground. He analyzed the threat.

 

Estimated height: 150 feet. Armor plating: heavy. Weak points: likely the optical sensor and the tread joints. My standard artillery will not penetrate the main chassis. Retreat is the tactical option.

 

He turned to follow the other students. But as he rotated his heavy frame, his enhanced auditory receptors picked up a sound over the grinding of the giant robot's treads.

 

A cry of pain.

 

Izuku looked back. Near the base of the Zero Pointer, pinned under a massive slab of concrete that had fallen from a crushed building, was the brown-haired girl from the entrance. Uraraka.

 

She was struggling frantically, her hands pressed against the rubble, but she was exhausted. The Zero Pointer was rolling forward, utterly indifferent to her presence. It was going to crush her.

 

Iida saw her too. He took a half-step forward, his engines revving, but fear froze him. He couldn't make it in time. It was suicide.

 

Izuku's analytical mind shut off.

 

The tactical option evaporated.

 

Click. Clunk. RRRRUUUMBLE.

 

Izuku's body underwent a radical shift. The hatches on his arms sealed shut. Deep within his legs, his internal avatar abandoned the artillery room and sprinted down a spiral staircase toward the engine room located in Izuku's calves. The avatar grabbed two heavy canisters of high-octane gasoline Izuku had ingested that morning and slammed them into the combustion chambers.

 

Vents opened on the backs of Izuku's heavy boots. Blue flame roared to life.

 

Izuku launched forward. He didn't run; he glided over the pavement like a hovercraft, propelled by the violent thrust of his internal combustion engine. He crossed the plaza in less than two seconds, a gray blur of smoke and metal.

 

He slid to a halt right beside the trapped girl.

 

Uraraka looked up, tears streaming down her dirty face. The shadow of the Zero Pointer's massive tread loomed over them, descending rapidly. "Run!" she sobbed. "It's too heavy!"

 

"Do not panic," Izuku's deep voice boomed.

 

He didn't try to lift the rubble. There was no time.

 

Instead, Izuku slammed his hands onto his own chest.

 

KACHUNK.

 

His entire chest cavity hinged open, the massive drawbridge lowering in a split second, revealing the warm, glowing, torch-lit foyer within.

 

Uraraka screamed as Izuku grabbed her by the collar of her jacket and hauled her violently toward his open chest.

 

The moment she crossed the invisible ten-foot threshold, reality warped. Uraraka's perspective inverted dizzily. The giant robot, the rubble, and Izuku's face ballooned to terrifying, impossible proportions. She was shrinking rapidly.

 

She tumbled through the air, bracing for a harsh impact.

 

Instead, she landed on something incredibly soft.

 

She bounced slightly, opening her eyes. She was no longer outside. She was sitting on a plush, red velvet Victorian couch.

 

She looked around in pure, unadulterated shock. She was in a room. The walls were made of sturdy gray stone, lined with bookshelves and warm, flickering fireplaces. There were medical supplies stacked neatly on a mahogany table. It was perfectly quiet, the apocalyptic noise of the Zero Pointer completely muted, replaced by the soft crackle of the hearth and a rhythmic, thumping warmth.

 

"Welcome to the Safe Room."

 

Uraraka shrieked, scrambling back on the couch. Standing in front of her was a tiny, glowing green boy. He looked exactly like the stoic giant who had grabbed her, but he was translucent and radiating a gentle warmth.

 

"I am the internal manager," the green avatar said, bowing politely. "Please remain seated. The exterior shell is about to undergo severe kinetic trauma."

 

"W-W-What?!" Uraraka stammered, looking up. High above her, through a massive rectangular opening in the ceiling of the room, she could see the sky, and the terrifying face of the giant robot descending.

 

Outside, Izuku locked his drawbridge shut with a massive CLANG.

 

He was alone under the shadow of the treads. He could not run. He was carrying a passenger, and he would not risk jostling her.

 

I am the Bastion, Izuku thought.

 

He planted his feet wide, sinking into a horse stance. He crossed his arms over his head, locking his joints in place. He willed every ounce of iron in his body to migrate to his skin, turning his epidermis into solid, blackened steel.

 

The Zero Pointer's tread slammed down directly on top of him.

 

The earth shattered. A massive crater formed in the street, blowing dust and debris hundreds of feet into the air.

 

In the observation room, the teachers leapt out of their seats.

 

"He's crushed!" Present Mic yelled.

 

"No," Aizawa said, his eyes narrowed, staring intently at the screen. "Look."

 

The dust began to clear.

 

The Zero Pointer's massive tread was halted in mid-air. It was grinding, gears screeching, hydraulics whining as it tried to push down.

 

Beneath the tread, standing in the center of the crater, was Izuku Midoriya.

 

His knees were buckled slightly. The pavement beneath his boots had turned to powder. His shirt was ripped to shreds, revealing skin that looked like cast iron. Smoke hissed from his joints. His eyes were glowing with a fierce, terrifying intensity.

 

He was holding the Zero Pointer up.

 

Inside the Safe Room, Uraraka felt the room vibrate slightly, but the structural integrity held perfectly. The avatar handed her a cup of water, completely unbothered.

 

"Heavy," Izuku grunted, his teeth bared in a fierce grin. "But not heavy enough."

 

Inside his engine room, the avatar abandoned Uraraka for a moment, sprinting down the stairs. It threw open the valves on the combustion chambers, dumping every remaining drop of gasoline into the furnace.

 

Vents on Izuku's elbows, shoulders, and calves violently blew open, blasting superheated blue fire.

 

Izuku didn't just hold the tread. He pushed back.

 

With a roar that sounded like a jet engine taking off, Izuku drove his fists upward. The sheer, concentrated thrust of his internal engines, combined with his unnatural density, acted like a hydraulic press in reverse.

 

He punched straight up into the bottom of the Zero Pointer's tread.

 

The metal buckled. Izuku didn't stop. He blew right through the tread, his body acting as a massive, rocket-propelled armor-piercing shell. He tore upward, ripping through the internal machinery, wires, and chassis of the colossal machine.

 

He rocketed straight up through the center of the robot, an unstoppable force of sheer density.

 

He burst out of the top of the Zero Pointer's head, shattering its red optical sensor into a million pieces, soaring fifty feet into the air on pillars of blue flame.

 

The giant machine groaned, sparks cascading from its ruined interior. It slowly, agonizingly tipped backward, crashing onto the empty street behind it with an earth-shattering explosion.

 

High in the sky, Izuku cut his engines. Gravity took hold.

 

He fell like a meteor, landing in the center of the plaza with a deafening CRASH. The impact sent a shockwave that knocked the remaining examinees off their feet.

 

Silence descended on Test Area B.

 

The smoke cleared. Izuku stood up slowly from the crater he had made. His skin hissed, radiating intense heat. The gray color slowly returned as the iron retracted deeper into his body. He looked exhausted, his chest heaving with deep, whirring breaths.

 

"TIME'S UP!" Present Mic's voice echoed across the city.

 

The examinees stared at Izuku in awe. He hadn't just destroyed the Zero Pointer. He had blown a hole straight through it from bottom to top.

 

Izuku ignored them. He tapped his chest.

 

Clack. Rumble.

 

The drawbridge opened.

 

Uraraka, sitting on the couch inside, looked up. The avatar waved at her. "You may exit now."

 

The couch suddenly tilted forward, transforming into a smooth ramp. Uraraka slid gently out of Izuku's chest, tumbling onto the pavement.

 

As soon as she cleared the ten-foot threshold, she expanded back to her normal size in a puff of displaced air. She sat on the ground, completely unharmed, holding a small, porcelain teacup the avatar had given her.

 

She looked up at Izuku. His chest closed, the locks sliding into place.

 

"Are you injured?" Izuku asked, wiping a smear of soot from his cheek.

 

"I... I'm fine," Uraraka whispered, looking at the teacup in her hands, then at the ruined mountain of metal behind him. "You... you're amazing."

 

Izuku didn't smile. He just nodded, a solid, reassuring gesture. "A fortress must protect its occupants."

 

From the sidelines, Tenya Iida adjusted his glasses, his hands trembling. He had misjudged this boy entirely. He wasn't just a noisy nuisance. He was a protector of the highest caliber.

 

"Excuse me," a sweet, elderly voice called out.

 

Recovery Girl walked into the plaza, leaning on her syringe-shaped cane. She walked up to Uraraka, assessing her, then turned her eyes to Izuku.

 

"Well, well. I saw the monitors, young man. That was quite the display. Let me heal those micro-fractures in your joints."

 

She leaned forward and planted a kiss on Izuku's arm.

 

Nothing happened.

 

Recovery Girl blinked. She kissed his arm again. Still nothing.

 

She frowned, tapping his arm with her cane. It made a metallic clink. "My goodness. My Quirk accelerates cellular regeneration. You don't have cells in there, do you? You're entirely inorganic beneath the dermis."

 

"I have a maintenance bay in my lower quadrant, ma'am," Izuku explained politely. "My avatar is currently welding the micro-fractures with a blowtorch and spare scrap metal. I will be fully repaired in three hours."

 

Recovery Girl threw her hands up in exasperation. "A blowtorch?! Well, I suppose that puts me out of a job. Go on, then! Back to the buses!"

 

As Izuku walked away, his heavy footsteps ringing out in the quiet plaza, the other examinees parted for him like the red sea. They looked at him with a mixture of reverence and fear.

 

 

 

One Week Later

 

Izuku sat at his desk in his bedroom. His notebook, VANGUARD BLUEPRINTS, was open. He was currently redesigning the internal plumbing of his Safe Room, considering adding a miniature water-filtration system so he wouldn't have to manually hand out teacups via the avatar.

 

"Izuku!"

 

Inko Midoriya burst into the room, tears streaming down her face. She was holding a thick envelope bearing the U.A. wax seal.

 

"It's here! The letter!"

 

Izuku took the envelope. It felt light. He carefully tore it open, making sure not to crush the contents with his dense fingers. A small metal disc fell onto his desk.

 

A holographic projection flickered to life.

 

Toshinori Yagi—All Might, in his full, muscle-bound glory—appeared on the projection. He was wearing a loud yellow suit.

 

"I AM HERE AS A PROJECTION!" All Might boomed. "Young Midoriya! You performed admirably on the written test! And in the practical exam, you scored a massive seventy-two villain points! That alone would easily secure your passing grade!"

 

Inko squealed in delight, covering her mouth.

 

"But wait!" All Might continued, pointing at the screen. "A hero course doesn't just grade on destruction! We grade on the spirit of heroism!"

 

The projection shifted, showing a clip of Uraraka talking to Present Mic after the exam.

 

"Excuse me," the holographic Uraraka said, looking nervous. "The heavy boy with the green hair... he saved me. He put me inside a literal safe room! Can I give him some of my points? He gave up time to protect me!"

 

The projection shifted back to All Might. "A hero who acts as an impenetrable shield for others! You didn't just save her, young Midoriya; you gave her absolute sanctuary! For that, you are awarded sixty RESCUE POINTS!"

 

A scoreboard appeared on the screen.

 

IZUKU MIDORIYA: 132 POINTS. FIRST PLACE.

 

"Welcome, young Midoriya," All Might said softly, his booming persona dropping for a moment, revealing genuine pride. "This is your hero academia."

 

The hologram fizzled out.

 

Inko threw her arms around Izuku's heavy neck, sobbing with joy. "I'm so proud of you, Izuku! So proud!"

 

Izuku hugged her back gently, careful not to squeeze too hard.

 

He looked at the blank wall of his bedroom. He had done it. He was in. But he knew this was only the foundation. U.A. High School was a place that produced swords—flashy, fast, and destructive heroes who struck down villains.

 

Izuku would let them be swords. He would let them take the glory and the spotlight.

 

He closed his eyes, listening to the steady, metallic heartbeat of the furnace within him.

 

He would be the Bastion. He would be the walls upon which the villains would break themselves. And he would never, ever fall.

 

 

 

The morning of Izuku Midoriya’s first day at U.A. High School began with a hearty breakfast of roasted cast iron, a bowl of high-grade anthracite coal, and a glass of synthetic motor oil.

 

He sat at the small kitchen table, chewing thoughtfully on a lug nut. To anyone else, the crunching sound would have been nauseating—like rocks in a blender—but to Inko Midoriya, it was just the sound of a growing boy getting his daily nutrients.

 

"Do you have everything, Izuku?" Inko asked, fluttering around the kitchen with a dustpan and brush, sweeping up the small flakes of rust that had shed from his clothes. "Notebooks? Pencils? Extra scrap metal for your internal reserves?"

 

"Yes, Mom," Izuku replied, his deep, resonant voice vibrating through the kitchen. He swallowed the lug nut. Deep within his torso, the faint, roaring crackle of his internal furnace flared to life, incinerating the iron and absorbing its dense properties to reinforce his outer dermis. "My armory is at eighty-five percent capacity, and the Safe Room is fully stocked with medical supplies, fresh blankets, and potable water."

 

"Good, good," Inko smiled, though a hint of worry remained in her eyes. She reached out and patted his shoulder. It was like patting a concrete pillar. "Just... promise me you won't push yourself too hard. I know you're sturdy, but U.A. is full of incredible students."

 

"I know," Izuku said, standing up. The chair groaned in relief as his four-hundred-and-fifty-pound frame lifted off it. "But a fortress doesn't need to push itself. It just needs to stand its ground."

 

He gave his mother a gentle, rigid hug, taking great care not to crush her ribs, and stepped out the front door.

 

The walk to the train station was a familiar routine. Civilians gave Izuku a wide berth. It wasn't just his size—though his broad, blocky shoulders and thick chest were imposing—it was the sound of him. Every step he took resonated with a heavy, mechanical thud, accompanied by the faint whirring of internal clockwork and the shifting of stone. He wore the standard U.A. uniform, heavily modified with reinforced canvas and expansion pleats, but underneath it, he looked like a boy carved from gray granite and wrought iron.

 

As he navigated the crowded train, he stood in the corner, locking his leg joints into place. He didn't need to hold a handrail. When the train jolted, passengers stumbled; Izuku remained utterly immovable, anchored to the floor by sheer density.

 

When he finally arrived at the towering gates of U.A. High, he paused, looking up at the massive glass building.

 

I am here, he thought. The perimeter has been breached. Commencing infiltration.

 

He navigated the maze-like hallways of the school until he found a door that was comically massive, painted with a giant red '1-A'.

 

He reached out and slid the door open.

 

Inside, the classroom was already lively. The tall boy with glasses from the entrance exam—Tenya Iida—was aggressively chopping his hands at Katsuki Bakugo, who was sitting with his feet propped up on his desk.

 

"Remove your feet from the desk this instant!" Iida barked. "It is disrespectful to the upperclassmen who sat there before you, and to the craftsmen who made it!"

 

"Shut up, four-eyes," Bakugo sneered, leaning back. "What middle school are you from, anyway? You an extra?"

 

Izuku stepped into the room.

 

THUD.

 

The heavy footfall silenced the immediate area. Iida turned, his eyes widening as he recognized Izuku. Bakugo's crimson eyes snapped to the doorway, and for a fraction of a second, his confident sneer faltered, replaced by a deep, instinctual grimace.

 

"Ah! You're the boy from the entrance exam!" Iida marched over, his robotic posture almost mirroring Izuku's heavy, rigid stance. "I am Tenya Iida from Somei Private Academy! I must apologize. I completely misjudged you during the orientation. You realized the true nature of the practical exam and prioritized the safety of your fellow examinees. You are a far superior student!"

 

"Hello, Iida," Izuku said calmly. "There is no need to apologize. Your tactical assessment of the orientation was logically sound based on the provided data. You simply lacked the structural capacity to safely intervene when the parameters changed."

 

Iida blinked, processing the very clinical, objective response. "I... see. Yes. Structural capacity."

 

"Oh! It's you!"

 

A cheerful voice chimed from the hallway. Ochaco Uraraka bounced into the doorway, her face lighting up when she saw Izuku.

 

"The walking safe house!" she beamed, stepping up to him. "I never got to properly thank you! You completely saved me from that giant robot. And, um, your inside room was really cozy! The little green ghost guy gave me chamomile tea!"

 

"It is standard protocol to hydrate civilians in shock," Izuku nodded, his face stoic, though a faint warmth radiated from his chest. "I am glad the Safe Room's suspension dampeners functioned correctly. I was concerned the kinetic transfer from punching the Zero Pointer would upset your tea."

 

Uraraka giggled, though she looked a bit bewildered by his extreme seriousness. "Nope! Didn't spill a drop!"

 

"If you're just here to make friends, you can pack up your things and leave."

 

The voice came from the floor.

 

The three students looked down. Lying in a bright yellow sleeping bag outside the doorway, looking entirely like a massive, depressed caterpillar, was a man with shaggy black hair and bloodshot eyes.

 

Izuku's analytical mind immediately fired up. Scruffy appearance. Capture weapon made of carbon-fiber and metal alloy wrapped around his neck. Goggles hidden under the scarf. Pro Hero: Eraserhead. Quirk: Erasure. An underground hero.

 

The man unzipped the sleeping bag, stepped out, and pulled a juice pouch from his pocket, slurping it loudly. "It took you lot eight seconds to quiet down. Time is a limited resource. You kids aren't rational enough."

 

He walked to the podium. "I'm Shota Aizawa. Your homeroom teacher."

 

The class collectively gasped—save for Izuku, who simply recalibrated his internal files on U.A.'s faculty.

 

"Right. Let's get to it," Aizawa said, pulling a blue U.A. P.E. uniform from his sleeping bag. "Put these on and head out to the training field."

 

 

 

The Quirk Apprehension Test

 

The sun beat down on the dirt field behind the school. Class 1-A stood in their gym uniforms, though Izuku's was bursting at the seams, the fabric stretched taut over his blocky, hardened physique.

 

Aizawa stood before them with a digital device in hand. "A Quirk Apprehension Test. In middle school, you did physical fitness tests without your Quirks. That's irrational. The Department of Education is lagging behind. Bakugo."

 

Aizawa tossed a softball to the explosive blonde. "You finished first in the practical exam. What was your farthest softball throw in middle school?"

 

"Sixty-seven meters," Bakugo scoffed.

 

"Try it with your Quirk. Anything goes, just stay in the circle."

 

Bakugo stepped into the chalk ring. He stretched his arms, a wicked grin spreading across his face. He wound up, and as he threw, a massive explosion detonated from his palm. "DIE!"

 

The ball rocketed into the sky, leaving a trail of smoke.

 

Aizawa held up the device. 705.2 meters.

 

The class erupted into excited chatter. "Seven hundred meters?! That's insane!" "We get to use our Quirks as much as we want? This looks fun!"

 

Aizawa's eyes narrowed. The air around him suddenly felt heavy, suffocatingly tense. "Fun? You have three years to become heroes. You think it's going to be games and playtime? Idiots. Whoever scores lowest across all eight events will be judged hopelessly lacking, and expelled."

 

A collective gasp of horror rippled through the students.

 

"Expelled?!" Uraraka cried. "But it's the first day! That's totally unfair!"

 

"Natural disasters are unfair. Villains are unfair. The world is saturated with unfairness," Aizawa retorted coldly. "If you wanted to go to a parlor to chat with your friends, you picked the wrong school. We're going to push you to the brink. Plus Ultra."

 

Izuku didn't flinch. He understood Aizawa's logic perfectly. A fortress that cracks under pressure is a tomb.

 

The tests began.

 

Test 1: 50-Meter Dash.

 

Iida ran it in 3.04 seconds, his engine legs blazing.

 

When it was Izuku’s turn, he lined up against a boy with a tail, Mashirao Ojiro. Ojiro looked at Izuku’s massive bulk, expecting the heavy boy to be incredibly slow.

 

"On your marks," the robot referee called. "Get set... Go!"

 

Izuku didn't run.

 

Click. Clunk. WHOOSH.

 

Twin exhaust ports snapped open on the backs of Izuku's calves. Inside, his avatar shoveled a massive dose of highly flammable, synthetic fuel into his engine room. Blue fire violently erupted from Izuku's legs.

 

The sheer force of the thrust cracked the starting line's pavement. Izuku didn't take a single step; he simply hovered two inches off the ground and rocketed forward in a rigid, standing pose, acting like a human missile. He crossed the finish line in a blur of gray and blue flame.

 

2.15 seconds.

 

He immediately cut the engines, his heavy boots slamming down into the dirt to arrest his momentum, skidding for ten feet and digging deep trenches into the field.

 

Ojiro crossed the line five seconds later, coughing on Izuku's exhaust smoke. "What... what are you made of?!"

 

"Iron, limestone, high-carbon steel, and trace amounts of titanium," Izuku replied plainly, dusting off his uniform.

 

Test 2: Grip Strength.

 

Izuku gripped the digital dynamometer. Inside his arm, thick, hydraulic pistons locked into place, the avatar pulling a heavy industrial lever. Izuku squeezed.

 

The digital counter climbed wildly: 200 kg... 500 kg... 900 kg...

 

With a sharp CRACK, the metal handle of the machine shattered, the plastic casing exploding into shrapnel.

 

Izuku looked at the broken machine in his hand. "I apologize, Aizawa-sensei. The structural integrity of this device was insufficient."

 

Aizawa just stared at him, his tired eyes betraying a flicker of profound curiosity.

 

Test 5: The Softball Throw.

 

Eventually, it was Izuku's turn to throw the ball.

 

He stepped into the circle. He looked at the softball in his massive hand. He could throw it manually, utilizing the hydraulic pistons in his arm, but that would only yield a few hundred meters. He needed explosive kinetic transfer. He needed his artillery.

 

He raised his right arm, pointing it straight up at a forty-five-degree angle.

 

Clack. Whirrrrr.

 

The skin on top of his forearm split open like a missile silo, revealing a dark, steel-lined barrel.

 

"What is he doing?" Mina Ashido whispered to Jiro. "Is his arm a gun?"

 

Izuku placed the softball over the open port. He allowed the ball to cross his ten-foot threshold. Instantly, the standard-sized softball shrank to the size of a BB pellet, dropping down into the darkness of his internal armory.

 

Inside, the green avatar caught the shrunken softball. It carried the ball over to the primary cannon—a massive, spring-loaded mechanism powered by a pressurized steam boiler. The avatar loaded the BB-sized softball into the chamber and grabbed the firing lanyard.

 

Outside, Izuku locked his stance, bracing for the recoil.

 

Aizawa's eyes suddenly flashed red. His scarf flared up, defying gravity.

 

Inside Izuku's armory, the avatar yanked the lanyard.

 

CLICK.

 

Nothing happened.

 

The firing mechanism jammed. The steam boiler's valves slammed shut. The massive, heavy iron locks on the armory doors slammed into place with deafening, grinding thuds, locking the avatar inside.

 

Outside, Izuku grunted, his eyes widening. He felt a profound, suffocating tightness in his chest. It wasn't pain, but rather the sensation of a hundred heavy steel doors being forcibly slammed shut and barred all at once. The faint, localized spatial field that surrounded his body—his threshold—evaporated.

 

The open port on his arm snapped shut on its own, locking tight.

 

Izuku stumbled a half-step, looking over his shoulder.

 

Aizawa was glaring at him, his glowing red eyes piercing through Izuku.

 

"I erased your Quirk," Aizawa said, his voice cold and flat.

 

The class gasped.

 

Izuku looked down at his body. He was still gray. He was still massive. He still weighed nearly five hundred pounds. His biological mutations were entirely intact. But the gears were locked. The spatial field was gone.

 

"Fascinating," Aizawa muttered, slowly blinking. His hair fell back to his shoulders. "I suspected as much when I reviewed your file."

 

Aizawa walked toward Izuku. "Your Quirk, 'Living Castle', is a rare dual-class anomaly. You have a permanent somatic mutation—your body is literally constructed of inorganic, dense materials. But your ability to shrink objects, store them, and manipulate your interior is an Emitter-type phenomenon."

 

Aizawa stopped a few feet away. "When I look at you, I cannot erase your physical mutations. Erasing your Quirk won't turn you back into flesh and blood, just like I can't erase Ojiro's tail. But I can erase the Emitter factor. I disabled your spatial field and locked your internal architecture."

 

Izuku nodded slowly, processing the data. "You sealed my drawbridges."

 

"Exactly," Aizawa said sharply. "Which brings me to my point. You relied entirely on your Emitter factor for that throw. You were going to use an internal cannon. What happens if a villain with a Quirk-canceling ability gets the drop on you? What happens if your internal mechanics jam? If your doors are locked, are you just a heavy paperweight?"

 

Bakugo snickered from the sidelines.

 

Izuku looked at Aizawa. He didn't feel insulted. He felt challenged. And a fortress always rises to a siege.

 

"May I throw the ball again, Sensei?" Izuku asked, his deep voice unwavering.

 

"Do it without the parlor tricks," Aizawa demanded. "Show me what the walls are made of."

 

Izuku stepped back to the center of the ring. He didn't open his arm ports. He didn't use the spatial field. He closed his eyes.

 

If the cannons are offline, the siege engine must become the battering ram.

 

Izuku planted his right foot. He engaged the manual hydraulic pistons in his waist, shoulders, and arm. He didn't need the internal avatar for this; this was purely the mechanical mutation of his joints.

 

He wound his arm back. The gears in his shoulder shrieked, winding tighter and tighter, compressing heavy steel coil springs built into his rotator cuff. He shifted his massive weight—four hundred and fifty pounds of dense stone and iron.

 

He threw.

 

BOOM!

 

The sound of his arm snapping forward was like a thunderclap. The sheer kinetic force of his heavy, dense arm striking the air created a shockwave that kicked up a cloud of dust around the pitching circle.

 

The softball exploded out of his hand, warping under the extreme physical pressure, rocketing into the stratosphere as a blurred streak.

 

Izuku exhaled slowly, the gears in his shoulder unwinding with a soft whir.

 

Aizawa checked his device. He turned the screen toward the class.

 

815.3 meters.

 

The class was dead silent.

 

Izuku looked at Aizawa. "Even if the gates are barred, Sensei, the walls will not fall."

 

Aizawa stared at the boy. A slow, terrifying grin crept across the underground hero's face. This kid. He's not a liability. He's a walking bunker.

 

"Not bad, kid," Aizawa muttered. "Get back in line."

 

Bakugo was shaking with rage. Eight hundred meters? Without even using that shrinking trick?! What the hell is he made of?!

 

By the end of the apprehension test, the results were displayed on the holographic board.

 

1. Momo Yaoyorozu

2. Shoto Todoroki

3. Katsuki Bakugo

4. Izuku Midoriya

 

Izuku had lost points on agility and jumping—his extreme weight made aerial maneuvers nearly impossible without burning excessive fuel—but his raw power and defensive stats easily secured him a top spot.

 

"By the way, I was lying about the expulsion," Aizawa said flatly, tucking his device away. "It was a rational deception to draw out the upper limits of your Quirks."

 

The class exploded in outrage, while Izuku simply nodded. It was a perfectly sound psychological tactic to test structural stress.

 

 

 

Afternoon - The Battle Trial

 

"I AM HERE!"

 

All Might burst through the classroom door, leaning back at an impossible angle, striking a Silver Age comic book pose. "COMING THROUGH THE DOOR LIKE A NORMAL PERSON!"

 

The class erupted in fanboyish cheers. Izuku just watched, admiring the hero's undeniable presence. All Might was the ultimate sword.

 

"Hero Basic Training!" All Might boomed. "Today, we're doing Combat Training! And for that, you'll need these!"

 

The wall slid open, revealing numbered briefcases.

 

"Your hero costumes! Based on your Quirk registrations and requests you submitted before school started! Get suited up and meet me at Ground Beta!"

 

Twenty minutes later, Class 1-A walked out of the tunnel into the fake urban city.

 

The costumes were flashy, colorful, and highly specialized. Uraraka wore her pink and black space suit. Bakugo wore his aggressive grenadier outfit with massive gauntlets.

 

Then came Izuku.

 

His footsteps announced him before he emerged from the shadows of the tunnel. CLANK. CLANK. CLANK.

 

Izuku didn't need armor. He was armor. To wear bulky metal plates would be entirely redundant. Instead, his costume was designed for utility, tactical advantage, and structural support.

 

He wore a dark gray, heavily reinforced tactical SWAT uniform. Thick canvas cargo pants laden with heavy pouches—filled with various types of metal scraps, screws, and ball bearings for ammunition. He wore a fitted, sleeveless black compression shirt that showed off his gray, stone-like skin. A heavy utility belt strapped across his waist held a massive, collapsible iron crowbar.

 

But the most notable feature was his chest and joints. His costume had large, perfectly measured square cutouts over his forearms, chest, and back. These cutouts allowed his internal "drawbridges" and "ports" to open unhindered. He looked like a heavily militarized, modern knight.

 

"Whoa, Midoriya, you look like a walking tank!" Kirishima grinned, punching his own hardened fists together.

 

"Thank you, Kirishima," Izuku said, adjusting a pouch of steel ball bearings. "The design prioritizes ammunition storage and thermal ventilation."

 

"Alright, embryos!" All Might shouted. "Today's lesson is a 2-on-2 indoor battle! Villains will guard a nuclear weapon inside the building! Heroes must infiltrate and either secure the weapon or capture the villains within fifteen minutes! Let's draw lots!"

 

Izuku stepped up and drew a ball. Team A.

 

He looked around. Uraraka held up a matching ball. "Yay! We're a team, Midoriya! The heavy hitter and the floater!"

 

Izuku nodded, pleased. Uraraka's Quirk provided excellent mobility, which offset his greatest weakness: slow traversal speed.

 

All Might drew the villain team. Team D.

 

Bakugo stepped forward, a savage, predatory grin splitting his face. He looked directly at Izuku, popping a small explosion in his palm. Iida stood beside him, adjusting his glasses, looking very serious about playing the role of a villain.

 

"Team A will be the Heroes! Team D will be the Villains!" All Might announced. "Villains, you have five minutes to set up inside the building! Heroes, prepare your strategy!"

 

 

 

The Siege Strategy

 

Izuku and Uraraka stood outside the five-story concrete building, looking over a crude map of the interior.

 

"Okay," Uraraka said, nervously tapping her fingers together. "Bakugo seems really mad at you, Midoriya. He's probably going to come straight for us, right? Iida will likely stay back to guard the weapon on the top floor."

 

"Correct," Izuku said, his voice a calm, deep rumble. "Bakugo possesses highly volatile, high-damage output. His psychological profile dictates he will attempt a direct, overwhelming assault to assert dominance."

 

"So, what do we do? If we both fight him, time will run out, and Iida wins."

 

"We do not fight him," Izuku said simply. "We bypass him. We will employ the Trojan Horse maneuver."

 

Uraraka tilted her head. "Trojan Horse?"

 

Izuku tapped his chest.

 

Clack. Whir.

 

His chest unlocked, the square cutout in his uniform accommodating the drawbridge perfectly. The heavy slab of skin and muscle lowered, revealing the warm, glowing interior of the Safe Room.

 

"You will enter the Safe Room," Izuku explained. "I will become an impenetrable transport vehicle. When we enter the building, Bakugo will attack me. He will assume I am alone. While he is focused on attempting to breach my outer walls, I will carry you past his line of sight. I have a concealed hatch on my upper back. When we pass the stairwell, I will open it. You will exit my body behind enemy lines, proceed to the fifth floor, and secure the weapon from Iida."

 

Uraraka stared at the open chest cavity, then at Izuku's utterly serious face.

 

"Wait," she said, her eyes wide. "You want me to go inside you? While you fight Bakugo?!"

 

"I will not fight him," Izuku corrected. "I will simply absorb his attacks. My structural density is more than capable of withstanding his explosions. You will be entirely safe inside. My internal suspension systems will negate the kinetic shockwaves."

 

Inside the Safe Room, the little green avatar appeared, waving at Uraraka and gesturing to the plush velvet couch.

 

Uraraka swallowed hard. It sounded crazy. But she remembered how safe she felt under the Zero Pointer.

 

"Okay," Uraraka said, her face setting with determination. "I trust you, Bastion."

 

Izuku paused. "Bastion?"

 

"Yeah! It means a fortress, right? It suits you!" She smiled. "Alright, let's do this!"

 

She stepped forward, crossing the ten-foot threshold. Instantly, the world warped. She shrank, tumbling forward through the air. The avatar caught her gently, setting her down on the velvet couch inside the stone-walled room.

 

CLANG.

 

The drawbridge shut behind her, the heavy deadbolts locking into place. The interior was immediately bathed in the warm, flickering light of the wall sconces. It was entirely silent, the sounds of the outside world completely muted.

 

"Please secure your seatbelt," the tiny green avatar instructed politely, pointing to a silk strap on the couch.

 

Outside, the buzzer sounded.

 

“HERO TEAM, COMMENCE ASSAULT!” All Might’s voice rang out through the speakers.

 

Izuku stood alone in front of the building. He cracked his heavy knuckles, the sound like grinding stones. He stepped through a window on the ground floor, his heavy boots crushing the glass into powder.

 

He didn't try to sneak. Stealth was an impossibility for a walking castle.

 

THUD. THUD. THUD.

 

He walked down the concrete hallway, his footsteps echoing ominously up the stairwells.

 

 

 

The Fifth Floor

 

Iida paced around the papier-mâché missile, holding his chin. "Bakugo! The hero team has entered! I can hear Midoriya's footsteps! We must fortify this room!"

 

Bakugo ignored him, marching toward the door, sparks popping from his gauntlets.

 

"Where are you going?!" Iida demanded. "Our objective is defense!"

 

"Shut up, extra," Bakugo snarled, his eyes wide with a manic, obsessive fury. "Deku thinks his little parlor tricks make him better than me. I'm going to blow his stupid stone body to dust."

 

Bakugo vanished into the hallway, sprinting down the stairs.

 

 

 

The Second Floor - The Ambush

 

Izuku turned a corner, his heavy frame filling the narrow hallway.

 

“DIE!”

 

Bakugo leaped from the shadows above, twisting in mid-air. He thrust his right palm forward, unleashing a massive, blinding explosion directly into Izuku's face.

 

The narrow hallway acted like a pressure cooker, amplifying the blast. The concrete walls scorched black, and the windows shattered outward from the sheer concussive force.

 

In the monitor room, the class gasped.

 

"He ambushed him! A surprise attack!" Ashido cried.

 

"That blast was huge! Is Midoriya okay?!" Kirishima yelled, leaning closer to the screen.

 

The smoke in the hallway began to clear.

 

Bakugo landed lightly on his feet, panting slightly, a savage grin on his face. "How's that, you damn nerd?! Still think your walls—"

 

Bakugo's voice died in his throat.

 

The smoke dissipated completely. Izuku was still standing there. He hadn't moved an inch.

 

The explosion had entirely incinerated the front of Izuku's black compression shirt, leaving his bare, gray chest exposed. But his skin wasn't burned. It wasn't even scratched.

 

Izuku had instantly shifted his biology upon impact, bringing dense, black iron to the surface of his skin. He looked like a statue forged in a volcanic furnace. The heat of the explosion was currently radiating off his iron skin in wavy, distorting lines, but he was utterly unharmed.

 

"A formidable preemptive strike, Kacchan," Izuku said, his voice devoid of anger, echoing deeply in the scorched hallway. "Your blast pressure is highly concentrated. However, against a target with my thermal and kinetic density, superficial explosions are ineffective."

 

Bakugo's eye twitched. The primal fear from his childhood—the fear of the unbreakable stone walls—bubbled up, rapidly converting into blind, incandescent rage.

 

"Shut up! Stop talking like a damn robot!" Bakugo screamed, launching himself forward.

 

He unleashed a flurry of explosions, weaving around Izuku like a hornet, blasting his ribs, his back, his knees. BOOM! BOOM! BOOM!

 

Izuku just stood there. He raised his arms, crossing them over his face to protect his eyes, entering a perfect, unyielding defensive guard.

 

Inside the Safe Room, Uraraka watched in awe. The room vibrated slightly, like a mild earthquake, but the sound of the explosions was just a dull, distant thump-thump-thump. The little green avatar was currently adjusting a thermostat on the wall, completely unbothered, while pouring her a fresh cup of tea.

 

He's not just a shield, Uraraka realized, watching the avatar work. He's a whole different world.

 

Outside, Bakugo backed away, panting heavily. The hallway was completely destroyed, the walls crumbling, the floor cratered.

 

Izuku lowered his arms. His iron skin was glowing cherry-red from the sheer heat of absorbing the blasts, acting as a massive heat sink. He took a slow, heavy step forward.

 

"Is that the extent of your payload?" Izuku asked calmly.

 

"Don't mock me!" Bakugo roared. He grabbed the large, grenade-shaped pin on his right gauntlet. "These gauntlets store my sweat. If I pull this pin, it unleashes a concentrated blast that will tear your stupid castle to the ground!"

 

In the monitor room, All Might grabbed the microphone. "Young Bakugo, stop! Are you trying to kill him?!"

 

"He won't die if he dodges!" Bakugo screamed, ripping the pin free.

 

A blinding pillar of fire and concussive force erupted from the gauntlet, tearing down the hallway like a roaring dragon. It consumed everything in its path, obliterating the walls and ripping the ceiling apart.

 

Izuku didn't dodge.

 

Engage primary anchors, Izuku commanded internally.

 

His heavy boots slammed into the floor, iron spikes shooting out from his soles, driving deep into the concrete foundation. He crossed his arms and lowered his center of gravity.

 

The blast hit him with the force of a freight train. The sheer pressure pushed him back, his metal boots carving two deep trenches into the concrete floor, screeching with horrific friction. The heat washed over him, turning his iron skin blindingly white.

 

But as the blast engulfed him, Izuku utilized the visual cover of the blinding light and smoke.

 

Avatar. Initiate the Trojan Horse.

 

Inside, the avatar saluted. It pulled a small lever near the ceiling of the Safe Room.

 

On Izuku's upper back, entirely shielded from Bakugo's blast by Izuku's massive, wide body, a small, square port slid open.

 

"Your turn, Uraraka!" the avatar squeaked. "Quickly!"

 

Uraraka nodded. She tapped her fingers together, using her Quirk on herself. "Zero Gravity!"

 

Weightless, she pushed off the velvet couch, floating upward toward the open hatch in the ceiling of the Safe Room. She passed through the thick layers of Izuku's iron and stone biology, popping out of the small port on his back like a tiny, floating doll.

 

The hallway was filled with roaring fire and smoke. But Uraraka was behind Izuku's massive, shielding body. The fire completely broke against Izuku's chest, parting around him like water around a boulder, leaving a perfectly safe wedge of clean air behind him.

 

Uraraka floated backward, crossing the ten-foot threshold.

 

Poof.

 

She instantly expanded to her full, normal size, landing softly in the stairwell directly behind the blast zone.

 

Bakugo, still firing his gauntlet, was completely blind to this. He was entirely focused on the unyielding silhouette of Izuku Midoriya standing in the fire.

 

Uraraka gave Izuku's massive, glowing back a quick salute, turned, and sprinted silently up the stairs toward the fifth floor.

 

 

 

The Aftermath of the Blast

 

The fire died down. The smoke began to clear through the blown-out windows.

 

Bakugo dropped his arm, gasping for breath, a manic smile on his face. "Ha... haha! Try tanking that, you quirkless—"

 

The smoke parted.

 

Izuku was still there.

 

He was pushed back twenty feet, his boots anchored into the torn concrete. His shirt was completely gone. His iron skin was glowing a violent, incandescent orange from the heat, radiating waves of thermal distortion.

 

He slowly lowered his arms. His joints hissed and popped, venting steam.

 

He looked at Bakugo, his eyes cold, calculating, and completely unfazed.

 

"Structural integrity holding," Izuku stated, his voice slightly distorted by the heat radiating from his throat. "Outer hull reached critical temperatures, but the internal sanctum remains breach-proof."

 

Bakugo dropped to his knees, his eyes wide, his pupils shrinking to pinpricks. It was impossible. He had used his absolute maximum firepower. He had unleashed a blast that could vaporize a building. And Deku was just standing there, reciting damage reports like a damn computer.

 

"W-What are you?" Bakugo whispered, his voice trembling with a mixture of rage and absolute terror.

 

"I am the Bastion," Izuku said, taking a slow, heavy step forward. His hot iron feet melted the linoleum floor. "And you have exhausted your artillery on a decoy."

 

Bakugo blinked. "Decoy...?"

 

“THE WEAPON HAS BEEN SECURED! HERO TEAM WINS!”

 

All Might’s booming voice echoed through the speakers.

 

Bakugo froze. He slowly turned his head to look up the stairwell.

 

On the fifth floor, Uraraka had surprised Iida. She used her zero gravity to float over his engine-powered charge, gently landing on the papier-mâché missile and hugging it tightly.

 

Bakugo looked back at Izuku. The realization hit him like a physical blow.

 

He hadn't been fighting a hero. He had been fighting a heavily armored transport vehicle. Izuku had never intended to defeat him; he simply needed to occupy his attention and absorb his firepower while the true objective was carried out right under his nose.

 

Bakugo felt completely, utterly outplayed. His strength was useless. His explosions were meaningless.

 

Izuku tapped his chest. His glowing orange skin slowly cooled, fading back to a dull, stony gray.

 

"A siege is not won by the sword alone, Kacchan," Izuku said, his voice echoing in the ruined hallway. "It is won by logistics, endurance, and knowing when to breach the walls."

 

In the monitor room, the class was in absolute uproar.

 

"Did you see that?!" Kaminari yelled, grabbing Mineta by the collar. "He just ate that giant explosion! And he snuck Uraraka out of his back!"

 

"It's a literal Trojan Horse!" Yaoyorozu gasped, her eyes wide with immense respect. "The tactical brilliance... he weaponized Bakugo's obsessive aggression, turning him into a distraction. Midoriya's spatial Quirk makes him the ultimate infiltrator, and his mutation makes him an immovable shield."

 

All Might stood silently, watching the monitor. He placed a hand over his own heart.

 

You truly are something else, young Midoriya, All Might thought, a massive smile spreading across his face. I thought you were just a shield. But a shield that thinks... a shield that outsmarts the sword... that is a terrifying weapon indeed.

 

Down in the ruined hallway, Bakugo remained on his knees, staring at the floor. The immovable object had won. And the unstoppable force had broken itself upon the walls.