What If Deku Created the Super Soldier Serum... But It Was Very Much Unstable

 

The wind howling across the rooftop of the forgotten office building felt sharper than usual, carrying with it the bitter chill of reality. Izuku Midoriya stood paralyzed, his worn red sneakers rooted to the concrete, his breath caught somewhere between his lungs and his throat. The sky above Musutafu was a bruised, indifferent violet, bleeding into the hazy twilight of late afternoon. 

Just moments ago, he had stood face-to-face with his god. 

Toshinori Yagi—the man the world knew as the invincible Symbol of Peace, All Might—had stood before him, smoke billowing from his emaciated frame, his golden aura stripped away to reveal a broken, bleeding man. And from the lips of that broken man, the ultimate, crushing verdict had been delivered.

“Can you be a hero without a Quirk? No. I don’t think you can.”

The words did not merely echo in Izuku’s mind; they carved themselves into the very architecture of his brain. They tore through the fragile, desperate hope he had nurtured for a decade. Pro heroes are always risking their lives, the skeletal man had said, his voice heavy with a grim, weary pragmatism. Some villains just can't be beaten without power. It's not bad to dream. But you also have to consider what's realistic, young man.

The rooftop access door had clicked shut five minutes ago, but the metallic sound still resonated in Izuku’s ears like a judge’s gavel. 

Izuku slowly dropped to his knees. The rough grit of the rooftop bit into his skin through his black school trousers, but he barely registered the sensation. His hands, trembling uncontrollably, fell to his sides. He stared blankly at the chain-link fence at the edge of the roof. 

Realistic.

He thought of his mother, looking at him with tears in her eyes, apologizing to a four-year-old boy instead of believing in him. I’m sorry, Izuku. I’m so sorry. 

He thought of Katsuki Bakugo, his palms crackling with explosive, violent heat, his crimson eyes filled with an arrogant, unyielding disdain. You’re worse than the rest of these rejects, Deku. You’re entirely Quirkless. Take a swan dive off the roof of the building and pray for a Quirk in your next life!

Izuku leaned forward, pressing his forehead against the cold concrete. A jagged, ragged breath escaped his lips, followed by a dry sob. He clutched at the fabric of his middle-school uniform, right over his heart, squeezing until his knuckles turned white. He wanted to cry. He wanted to weep until his tear ducts ran dry, just as he always did. He waited for the familiar rush of hot, pathetic tears.

But they didn't come.

Instead, a strange, profound silence settled over him. It was a cold, absolute vacuum. The weeping, stuttering, hopelessly optimistic boy who had climbed the stairs to this roof was dead. He had been suffocated by the heavy, iron-clad logic of the Symbol of Peace. 

You need power, the silence whispered. 

Izuku pushed himself off the concrete. He didn't look over the edge of the roof as Bakugo had suggested. He didn't look up at the sky. He looked at his own trembling hands. They were small. Weak. Normal. Unremarkable. 

"Power," Izuku muttered, his voice cracking, devoid of its usual melodic pitch. The word felt strange in his mouth. "It's all just... power. Genetic lotteries. Biology."

He turned and walked toward the stairwell. His descent was methodical, mechanical. By the time he reached the busy streets below, a distant explosion echoed through the city—the sound of the sludge villain incident that, in another life, would have been his crucible. Izuku didn't run toward the smoke. He didn't pull out Hero Analysis for the Future No. 13 to take notes. He just walked home, his emerald eyes dark, fixed on the pavement, a terrifying, quiet calculus beginning to whir to life in the back of his mind.

Izuku’s bedroom was a shrine. Floor-to-ceiling posters of All Might in his Silver, Golden, and Bronze Age costumes plastered the walls. Action figures stood in perfectly aligned rows on his shelves. Limited edition bedsheets, replica capes, and commemorative plaques filled every available square inch of the room. It was a monument to a god who had forsaken him.

Standing in the center of the room, still wearing his school uniform, Izuku looked around. The bright reds, blues, and yellows suddenly made him feel physically nauseous. The blinding, primary-color optimism felt like a mockery. 

He walked over to the largest poster—All Might doing his signature laugh, pointing a colossal finger forward with the caption: I AM HERE!

Izuku reached up, his fingers gripping the glossy paper. With a sharp, sudden, and violent pull, he tore it down. The sound of tearing paper was loud in the quiet apartment. He threw the crumpled mess to the floor. Then he moved to the next poster. Tear. The next. Tear. He swept his arm across his desk, sending dozens of meticulously maintained action figures crashing to the floor. Their plastic bodies bounced and clattered against the hardwood. 

He didn't stop until the walls were bare, the cheap beige wallpaper exposed like bare skin. He gathered the merchandise, stuffed it all into heavy black garbage bags, and shoved them deep into his closet, locking the door.

He sat heavily at his desk. The only thing left on the wooden surface was a stack of thirteen notebooks. Hero Analysis for the Future. 

Izuku opened the latest notebook, its cover still slightly singed and smelling of burnt sugar from Bakugo's explosion earlier that day. He flipped through the pages. Pages and pages of meticulous, obsessive detail. He had analyzed Mt. Lady's gigantification, plotting out the square-cube law and how her bone density must instantaneously shift to support her mass. He had diagrammed Kamui Woods' cellular structure, theorizing how his body processed carbon to generate wood pulp. He had mapped out the exact kinetic output of Bakugo’s nitroglycerin-like sweat.

He ran his fingers over the ink. 

"Quirks are physical abilities," Izuku whispered into the stillness of his room. 

It was a fundamental truth taught in elementary school. The arrival of the glowing baby in Qing Qing City wasn't magic. It was evolution. A biological mutation. The extra joint in the pinky toe was the marker of the old breed of humanity; the lack of it signaled the new, genetically superior breed. Quirks were biology. They were bound by the laws of physics, chemistry, and thermodynamics. 

They were organs. They were hormones. They were chemical reactions in the body.

Izuku grabbed a fresh, blank notebook from his drawer. He clicked his pen. 

If a Quirk was nothing more than an advanced biological function... then it could be replicated. Synthesized. If humans could engineer steroids to push muscles beyond natural limits, if they could create adrenaline epinephrine pens to restart a heart, if they could manipulate genetic structures in agriculture... why couldn't the human body be chemically forced to achieve superhuman output?

"If nature didn't give it to me," Izuku said, the pen hovering over the first blank page, his eyes narrowing with a dark, intense fever, "I'll just have to make it myself."

At the top of the page, he wrote: Project: Alpha.

The first month of Izuku Midoriya’s descent into obsession went largely unnoticed by the world. To his mother, Inko, he simply seemed a bit more withdrawn, a bit more studious. To his classmates at Aldera Junior High, the useless, stuttering Deku had simply learned to keep his head down.

Bakugo noticed something, though he couldn't put his finger on it. Deku no longer flinched when Bakugo slammed his hands on his desk. Deku just stared through him, his eyes distant, calculating, as if Bakugo were no longer a person, but merely an interesting chemical reaction to be observed. 

Izuku was no longer paying attention to middle-school algebra or history. Underneath his textbooks, he was reading collegiate-level material he had pirated from the internet. Advanced Endocrinology. Myostatin Inhibition in Mammals. Cellular Regeneration and ATP Manipulation. 

He was hunting for the biological mechanisms of strength. 

He realized quickly that a Quirk couldn't just be downloaded into his DNA. He couldn't give himself telekinesis or fire breath. But raw physical enhancement? Super-strength, hyper-speed, enhanced durability? That was just a matter of removing the body's natural limiters and supercharging the metabolic rate. 

His first major hurdle was supplies. Theoretical biology was useless without practical chemistry.

Aldera Junior High’s chemistry lab was underfunded, but it had the basics. Izuku began staying late, offering to help the elderly science teacher, Mr. Honda, clean the lab equipment. Mr. Honda was thrilled to have a volunteer, completely unaware that while his back was turned, the quiet, curly-haired boy was siphoning off hydrochloric acid, sodium hydroxide, raw ethanol, and various heavy metal salts into nondescript water bottles in his backpack.

But high school chemistry supplies weren't enough. He needed pharmaceutical-grade compounds. He needed adrenaline. He needed synthetic growth hormones. He needed access to the dark web.

Izuku spent two weeks teaching himself basic cybersecurity, utilizing proxy servers and Tor networks to access illicit online black markets. He used his life savings—the allowance he had diligently saved for years to buy expensive Hero merchandise—to purchase Bitcoin. He ordered unregulated chemical precursors from shady distributors in Russia and Southeast Asia. He ordered medical-grade centrifuges, precise glass pipettes, beakers, bunsen burners, and a digital microscope, having them shipped to an abandoned post office box across town.

Late at night, while Inko slept, Izuku transformed his bedroom. 

The space where All Might posters once hung was now covered in whiteboards filled with sprawling, chaotic chemical equations. His desk was retrofitted into a titration station. The room permanently smelled of bleach, copper, and something sharp and acrid that made Izuku’s eyes water.

His sleeping patterns disintegrated. He was running on three hours a night, kept awake by the manic energy of his work and the gallons of cheap black coffee he consumed. 

"Izuku, honey?" Inko knocked on his locked door one evening in November, three months after the rooftop incident. Her voice was laced with worry. "You've been in there all weekend. You hardly touched your dinner. Are you okay?"

Izuku paused, a glass beaker filled with a bubbling, muddy-brown liquid in his gloved hand. He wore heavy safety goggles over his eyes, and a cheap respirator mask hung around his neck. The bags under his eyes were bruised and purple, his skin taking on a sickly, pale pallor from lack of sunlight.

"I'm fine, Mom!" he called out, injecting a false, bright cheerfulness into his tone. "Just... working on a really big science project for school. It's extra credit!"

"Oh. Well... don't push yourself too hard, okay? I worry."

"I won't. Love you, Mom."

He heard her footsteps retreat down the hall. Izuku’s smile dropped instantly. He turned back to the beaker. He added three drops of a synthesized myostatin-inhibiting peptide. The muddy liquid hissed, turning a violent shade of orange before suddenly solidifying into a useless, charred lump of chemical waste. 

Izuku cursed under his breath, tossing the beaker into a waste bin filled with dozens of similar failures. 

"The cellular degradation is too fast," he muttered, aggressively scrubbing a hand through his unkempt green curls. He turned to his whiteboard, aggressively crossing out a long chain of molecular diagrams. "The human body naturally limits muscle output to prevent the tendons from tearing off the bone. If I chemically override the limiter using synthetic adrenaline and hyper-oxygenate the blood... the muscles will contract with superhuman force. But the resulting metabolic heat and lactic acid buildup will cook the cells alive from the inside out."

He stared at his hands. If he injected his current formula, he would gain the strength of a Pro Hero for about five seconds before his heart exploded.

"I need a stabilizer. Something that forces rapid cellular regeneration simultaneous to the muscle breakdown. Like... like Nomu."

He paused. The word had slipped out. He had read obscure, heavily redacted police reports on underground fighting rings and illegal quirk-enhancement drugs like Trigger. But he wasn't making Trigger. Trigger enhanced existing Quirk factors. Izuku didn't have a Quirk factor. He was trying to mutate baseline human biology from the ground up.

He turned his attention to his makeshift vivarium. Inside a glass terrarium sat three white laboratory mice. He had bought them at a pet store. He called them Test Subjects 1, 2, and 3.

He synthesized a new batch, this time lowering the adrenaline quotient and increasing the regenerative peptide derived from an illegal starfish-stem-cell extract he had bought online. He drew a microscopic amount of the pale yellow liquid into a syringe.

He carefully extracted Test Subject 1, a small, twitchy mouse, and injected the serum.

For ten seconds, nothing happened. Izuku leaned in, holding his breath, his notebook ready.

Then, the mouse shrieked. It was a horrible, high-pitched sound. The creature's muscles suddenly began to bulge, stretching the skin tight. Its eyes went bloodshot. It began violently throwing itself against the glass of the terrarium, denting the reinforced mesh with terrifying, unnatural strength. It moved faster than the human eye could track. 

Izuku’s heart hammered against his ribs. It works, he thought, a wild, dangerous grin spreading across his face. It actually works.

But the triumph was short-lived. Thirty seconds later, the mouse stopped moving. It began to seize violently. Blood leaked from its eyes and nose. With a sickening pop, the creature's chest cavity ruptured from the immense internal pressure, leaving a gory, lifeless mess on the woodchips.

Izuku stared at the dead animal. His grin slowly faded into a grim, stoic line. 

He didn't flinch. He didn't look away in horror. A year ago, he would have cried over the poor creature. Now, he simply picked up his pen.

Subject 1: Catastrophic cardiovascular failure. Tensile strength increased by approximately 800%. Stabilizer failed. Adjusting the alkaline buffer.

He threw the dead mouse into a bio-hazard bag, cleaned the cage, and started again.

Month six. Winter had settled over Musutafu, blanketing the city in freezing rain. Inside his bedroom, the temperature was a sweltering eighty degrees, generated by the constant burning of bunsen burners and hot plates. 

Izuku was deteriorating physically, even as his intellect sharpened into a lethal, hyper-focused weapon. He had lost weight, his collarbones jutting sharply against his skin. His fingers were covered in chemical burns and tiny cuts from broken glass. He wore long sleeves at all times to hide the damage from his mother and his classmates.

At school, he was a ghost. He took his notes, passed his exams with flawless, perfect scores, and spoke to no one. Bakugo had tried to corner him once in the hallway, grabbing him by the collar, explosions popping in his palms.

“What the hell is your problem lately, Deku? You think you’re better than me looking down like that?!”

Izuku had simply stared at Bakugo's hand. He analyzed the sweat glands, calculating the exact amount of nitroglycerin being secreted. He looked up into Bakugo's furious crimson eyes. Izuku didn't see a childhood friend anymore. He didn't see an unbeatable rival. He saw a biological anomaly. 

“Your Quirk is heavily dependent on hydration and vasodilation, Katsuki,” Izuku had said, his voice flat, devoid of its usual tremor. “If I were to sever your radial artery, your blood pressure would drop so rapidly that you wouldn't be able to secrete the sweat required for an ignition. You'd be powerless in less than forty seconds.”

Bakugo had frozen, a genuine flicker of shock and unease crossing his face. The sheer, chilling apathy in Deku's eyes was something alien. Bakugo had dropped him, scoffing loudly to cover his discomfort, and walked away.

That interaction only fueled Izuku. He was so close. The equations were balancing out. 

His latest iteration, Formula 47, had managed to keep Test Subject 3 alive for a full five minutes of hyper-enhanced activity before the internal hemorrhaging began. He was managing the metabolic heat, but the sheer ferocity of the chemical reaction was tearing the muscle fibers apart faster than the stem-cells could repair them. 

He needed a bonding agent. Something to bridge the gap between human cellular structure and the violent chemical catalyst. 

He found the answer deep in a restricted medical database from the United States, buried in a research paper on experimental treatments for muscular dystrophy. Liquid Fullerenes. Carbon nanotubes suspended in a biologically inert fluid. If he could integrate the nanotubes into the serum, they would bind to his muscle fibers upon injection, acting as a microscopic, indestructible scaffolding. They would hold his muscles together while the serum ripped them apart and rebuilt them.

It was highly experimental. It was incredibly toxic if not synthesized correctly. It cost him the last of his cryptocurrency to acquire the raw materials from a black-market medical supplier in Hokkaido. 

When the discreet, unmarked package arrived in the mail, Izuku locked his bedroom door and didn't come out for three days.

Month ten. It was April. The cherry blossoms were beginning to bloom across the city. The UA High School Entrance Exam was exactly one week away.

Izuku Midoriya stood over his desk. The room was bathed in the harsh, sterile glow of an LED desk lamp. The air was thick, heavy with anticipation and the sharp scent of ozone. 

In the center of the desk, secured in an iron clamp over a low flame, was a boiling flask. Inside, a liquid was rapidly changing state. 

Izuku carefully adjusted the glass stopcock of a burette, allowing exactly three drops of the liquid fullerene compound to fall into the boiling mixture. 

One. Two. Three.

He killed the flame. He grabbed a glass stirring rod and began to agitate the mixture. 

The reaction was instantaneous. The muddy, volatile brown liquid hissed violently, emitting a small plume of white steam. The color rapidly began to shift. Brown turned to murky yellow, then to a sickly, pale chartreuse, before finally settling into a vibrant, luminescent, emerald green. 

It was perfectly clear. It was entirely stable. It caught the light of the desk lamp, glowing with an almost radioactive intensity. 

Izuku slowly removed the stirring rod. He brought the flask up to eye level. The green liquid shifted smoothly against the glass, heavy and viscous, like liquid mercury. 

He had done it. 

After ten months of agonizing, sleep-deprived, borderline psychotic dedication, he had broken the code. He had synthesized physical superiority. He had created the world's first bio-chemical Quirk.

"Serum Alpha," Izuku breathed, his voice barely above a whisper. 

He set the flask down. His hands were shaking. He wasn't shaking out of fear; he was shaking with an overwhelming, intoxicating surge of triumph. The ghosts of the past ten months—All Might’s crushing rejection, Bakugo’s cruel laughter, his mother’s pitying tears—all shattered in the face of the glowing green vial on his desk. 

They had told him to be realistic. They had told him he was nothing. A Quirkless, useless Deku. 

I am a god in a laboratory, Izuku thought, a manic, dangerous energy coursing through his veins. I have built what nature denied me. I have engineered a miracle.

He moved with rehearsed precision. He opened a drawer and pulled out a sterile, heavy-duty medical syringe. He removed the plastic cap with his teeth, spitting it onto the floor. He dipped the long, viciously sharp steel needle into the flask and slowly pulled back the plunger. 

The heavy green liquid filled the barrel of the syringe, fifty milliliters of pure, synthesized power. 

Izuku tapped the side of the syringe, flicking a small air bubble out of the needle. 

He walked over to the full-length mirror attached to the back of his bedroom door. He looked at himself. 

He looked terrible. He was dangerously thin, his collarbones sharp, his skin pale and sallow. Dark circles ringed his feverish, bloodshot emerald eyes. His wild green hair was a tangled, unwashed mess. He looked like a junkie, a madman, a broken boy pushed far beyond the brink of sanity. 

But behind the exhaustion, there was a terrifying resolve. The stuttering, timid fanboy who had desperately asked for a hero's validation was dead. The creature staring back in the mirror was cold, calculated, and willing to pay any price for power.

"You want realistic?" Izuku whispered to the reflection, speaking to the phantom of All Might. "I'll show you realistic."

He unbuttoned the cuff of his left sleeve and rolled it up past his elbow. He grabbed a rubber tourniquet from his desk and bit down on one end, pulling it tight around his bicep with his right hand. The veins in his pale forearm popped to the surface, thin and blue.

He raised the syringe. The glowing green liquid seemed to pulse in the dim light. 

He didn't know exactly what was about to happen. His animal testing had proven the raw kinetic potential of the serum, but human biology was exponentially more complex. The carbon nanotubes were theoretical. The stabilizer might fail. The injection could trigger a massive cardiac arrest. It could melt his nervous system. It could kill him painfully in less than ten seconds. 

Izuku didn't care. To live as a powerless victim in a world of gods was a fate worse than death. 

He lined up the tip of the needle with the prominent medial cubital vein in the crook of his elbow. 

He didn't close his eyes. He watched himself in the mirror. He wanted to witness the exact moment he ceased to be Izuku Midoriya, the Quirkless Deku. 

He took one final, deep breath.

He shoved the needle into his vein. 

He didn't flinch at the pain of the steel piercing his skin. He placed his thumb over the plunger. 

"Plus Ultra," Izuku whispered, his lips curling into a manic, feral smile.

He depressed the plunger, forcing the heavy, glowing green Serum Alpha directly into his bloodstream.

The moment the liquid entered his vein, a sensation unlike anything he had ever felt—unlike anything humanly possible—exploded inside him. It was as if he had injected liquid hellfire. 

Izuku ripped the syringe out of his arm, dropping it to the floor. The glass shattered.

He stumbled back, his hands flying to his chest. His heart gave a violent, unnatural shudder. It didn't beat; it slammed against his ribs like a sledgehammer. Thud-THUD. Thud-THUD. 

"G-Gahh!" A choked, wet gasp tore from his throat. 

He fell to his knees, grabbing the edges of his desk, white-knuckling the wood. The veins in his arms, previously blue and faint, suddenly bulged, turning a sickening, toxic shade of dark green. The discoloration raced up his arms, spreading across his chest and up his neck, mapping his circulatory system in vibrant, terrifying emerald.

Pain. It was a pure, blinding, all-consuming agony. It felt as though every single cell in his body was being submerged in boiling acid and electrocuted simultaneously. The carbon nanotubes were forcing their way into his muscle fibers, shredding and binding his tissue at a microscopic level. 

Izuku threw his head back and opened his mouth to scream, but no sound came out. His vocal cords were instantly thickening, his throat constricting as his muscles began to rapidly, violently expand. 

He looked at his arms. His thin, scrawny forearms were swelling, the skin stretching taut. The muscle mass was doubling, tripling in seconds. He could hear the horrifying, wet sound of his own flesh tearing and instantly regenerating. His bones cracked loudly, micro-fractures splintering and healing denser, thicker, heavier.

The heat was unbearable. Sweat poured off his body, instantly evaporating into a faint, localized steam that rose from his shoulders. 

His vision went entirely red, then blindingly white. The synthetic adrenaline hit his brain like a freight train, completely overriding his nervous system. The pain was suddenly violently swept away by an apocalyptic rush of dopamine, endorphins, and pure, unadulterated aggression. 

He let go of the desk and stood up. 

He didn't just stand. He launched himself upright. The sheer force of his legs straightening propelled him upward with such violence that his head nearly clipped the ceiling. He landed on his bare feet, the wooden floorboards beneath him audibly groaning, spiderweb cracks forming under his heels from his vastly increased density.

Izuku stood in the center of the room, panting heavily. The air entering his lungs felt like cold ice; the air leaving felt like a furnace. 

He looked back into the mirror. 

The frail, sickly boy was gone. In his place stood a predator. His chest was broad, his shoulders heavily muscled, his arms corded with thick, dense sinew. The toxic green veins pulsed rhythmically against his flushed skin. His eyes... his eyes were terrifying. The pupils were blown wide, a ring of emerald fire surrounding an ocean of black, bloodshot and feral. 

He felt a terrifying, buzzing energy vibrating beneath his skin. It was an itch that demanded to be scratched. It was violence. It was power. 

Izuku slowly raised his right hand. He clenched it into a fist. The tendons in his arm snapped taut like steel cables. 

He looked at the solid oak desk he had sat at for years. Without thinking, operating purely on the intoxicating, chemical high racing through his brain, he swung his fist downward. 

He didn't put his weight into it. It was a casual, backhanded strike.

CRACK-BOOM.

The impact sounded like a shotgun blast. The oak desk exploded. It didn't just break; it violently splintered into hundreds of jagged pieces, the kinetic force completely shattering the heavy wood and driving a crater into the floorboards beneath it. Wood chips flew across the room like shrapnel, embedding themselves in the drywall.

Izuku stood frozen, staring at his fist. There was not a single scratch on his knuckles. The carbon-nanotube laced muscle and hyper-dense bone had effortlessly absorbed the kinetic recoil. 

A low, rumbling sound began to build in his chest. It started as a chuckle, dark and breathy, before escalating into a full-throated, echoing laugh. It wasn't the heroic, booming laugh of All Might. It was the unhinged, delirious laugh of a boy who had just rewritten the laws of his own reality.

The silence of the apartment was shattered. Inko knocked frantically on the door.

"Izuku?! Izuku, what was that noise? Are you okay?! Open the door!"

The sound of his mother's terrified voice cut through the chemical haze in his brain, but only slightly. The adrenaline made her voice sound distant, unimportant. The serum was screaming at him to move. To run. To hit something else. The raw energy was physically burning him; he needed to expend it.

He looked at his bedroom window. It was closed, locked, three stories above the street level. 

Izuku didn't bother opening it. 

He took one step back, his heavy muscles coiling like a spring, and launched himself forward. He shattered the window frame, the glass exploding outward into the cool night air. 

He was in freefall, plummeting three stories down toward the concrete alleyway behind their apartment complex. The wind rushed past his face. He felt no fear. He felt invincible. 

He twisted in the air, landing on his feet. The impact cratered the asphalt, spiderwebbing the concrete in a three-foot radius. The shockwave blew the loose trash in the alleyway backward. Izuku slowly stood up from the crouch, the green veins on his neck pulsing violently. 

He looked at his hands, then looked down the dark, narrow alley leading to the city streets. The world felt painfully slow. He could hear a siren miles away. He could hear the hum of the electrical wires above him. 

He was powerful. He was perfect. 

With a burst of speed that tore a divot out of the pavement, a blur of green and black shot into the night, leaving nothing but shattered glass and the lingering, acidic smell of chemicals in its wake. The monster was loose, and the countdown to the crash had begun.

The night air of Musutafu was usually a stagnant, humid thing, heavy with the exhaust of millions of commuters and the low, ever-present hum of urban sprawl. But right now, to Izuku Midoriya, the air felt thick, tangible, like a fluid he could swim through. 

He was running. No, "running" was a word for ordinary humans. He was launching himself, devouring the distance between city blocks with a predatory, loping gait that bordered on flight.

Each time the soles of his bare feet struck the asphalt, a shockwave rippled out, the kinetic force denting the pavement and propelling him forward thirty, forty, fifty feet at a time. The world around him had dissolved into a smear of neon streaks—the blinding yellows of streetlamps, the harsh reds of traffic lights, the dull blues of storefront signs. They dragged across his vision like wet paint on a canvas. 

I am fast. I am so fast.

The thought was loud, echoing in the cavern of his hyper-accelerated mind. A manic, breathless laugh tore its way out of his throat, the sound instantly whipped away by the gale-force winds of his own momentum. 

He didn't feel the cold. He didn't feel the sharp debris of the streets cutting into his bare soles. All he felt was the roaring, explosive furnace of his own heart, pumping the heavy, emerald-laced blood through his expanded veins. The Serum Alpha was singing in his system. It was a chaotic, beautiful symphony of synthetic adrenaline, myostatin inhibitors, and liquid fullerenes binding his tearing muscle fibers into microscopic cables of indestructible carbon.

Up ahead, a brick wall loomed at the end of a blind alley. A normal person would brake. A pro-hero might grapple over it. 

Izuku didn't slow down. He accelerated. 

At the last possible fraction of a second, he threw his body forward, his right foot slamming into the vertical face of the brick. He didn't bounce off; his momentum and vastly increased mass carried him upward. He ran three steps straight up the vertical surface, his toes digging into the mortar like steel pitons, before kicking backward. He backflipped through the air, clearing the three-story building with a sickening grace, and landed soundlessly on the gravel roof.

He uncoiled from his landing, his chest heaving, steam literally rolling off his bare, heavily muscled shoulders. The metabolic heat he was generating was absurd. His body was a nuclear reactor running without cooling rods. 

He walked to the edge of the roof and looked down at the city. 

The perspective shift was staggering. For fourteen years, Izuku had walked these streets looking up. He had looked up at All Might. He had looked up at Bakugo. He had looked up at the towering, impossible heights of the heroes who possessed the genetic lottery tickets he had been denied. He had been a mouse scurry in the shadows of giants.

Now, looking down at the cars crawling like metallic beetles, at the pedestrians frozen like statues in the crosswalks... he felt no awe. He felt a dark, swelling sense of superiority. 

They are so slow, the chemical high whispered in his mind. They are so fragile. If you wanted to, you could break them all.

Izuku blinked, his bloodshot eyes widening slightly as the thought registered. Where had that come from? It was a cruel, callous thought—one that belonged to Katsuki Bakugo, not Izuku Midoriya. But the sudden surge of synthetic dopamine and testosterone was drowning out his prefrontal cortex. His empathy, his timidity, his lifelong habit of shrinking into himself... the serum had burned it all away, leaving behind a raw, primal predator. 

He clenched his fists, listening to the horrifyingly heavy sound of his own knuckles popping. He needed to test this. He needed a metric, a baseline. He needed to know exactly where he stood in the hierarchy of power.

Suddenly, his ears twitched. 

His auditory canals had expanded, his eardrums reacting to frequencies far beyond human capability. Beneath the white noise of traffic and distant sirens, he heard a sound. It was three blocks away, down in the narrow, claustrophobic labyrinth of the commercial district's back alleys.

A scuffle. The sound of a heavy fabric tearing. The sharp, panicked intake of breath. 

"P-Please! I don't have anything else!" 

It was a woman's voice. Shrill. Terrified. 

"Shut up, bitch. The watch. Give me the watch or I'll open up your throat."

A man's voice. Gravelly. Malicious.

Izuku’s pupils dilated, the emerald ring of his irises burning like flares in the dark. The hero fanboy inside him screamed, A crime! Someone needs help! But the monstrous, chemical-drenched beast that now piloted his body didn't care about saving the woman. It only heard one thing: Prey.

Izuku stepped off the ledge. 

Gravity tried to claim him, but he was moving too fast. He plummeted three stories, twisting mid-air to grab the iron railing of a fire escape. The metal shrieked and warped under his grip as he used it to pendulum his body forward, launching himself across the street. He landed on the side of a concrete telephone pole, rebounding instantly, ricocheting through the urban canyon like a pinball of pure, destructive kinetic energy.

He covered the three blocks in four seconds. 

He crashed into the alleyway, landing in a three-point crouch. The sheer force of his arrival kicked up a cloud of dust and displaced a rusted dumpster, sending it skidding a foot backward with a harsh screech of metal against concrete.

The alley went dead silent. 

Twenty feet away, illuminated by the flickering, sickly yellow light of a broken streetlamp, stood the mugger. He was a massive man, easily six-foot-five, his Quirk evident by the thick, jagged protrusions of gray stone jutting out from his forearms and jawline. In one of his massive, rocky hands, he held a young woman by the collar of her blouse, lifting her effortlessly off the ground. In his other hand, a blade of sharpened rock extended from his wrist, pressed directly against her carotid artery.

The mugger turned his head, his small, piggish eyes squinting through the dust at the figure that had just fallen from the sky.

"The hell?" the mugger grunted. "Another hero wannabe? Buzz off, kid. This ain't your business."

Izuku stood up slowly. 

The shadows clung to him. He didn't look like a hero. He wasn't wearing a brightly colored spandex suit. He was wearing the torn, black trousers of an Aldera Junior High uniform, his chest bare, violently muscled, and glowing with a network of toxic green veins. 

"Put her down," Izuku said. 

The words startled even him. His voice had dropped an entire octave. It wasn't a request. It didn't have the booming, reassuring warmth of All Might's "I am here." It sounded like a death sentence. It was a low, vibrating growl that seemed to rattle the loose gravel in the alley.

The mugger sneered, his rocky jaw grinding. "Or what, freak? You gonna stop me? I've got a hardened-stone Quirk! Bullets bounce off me!"

To prove his point, the mugger tossed the woman aside like a ragdoll. She hit the brick wall and slumped to the ground, sobbing, scrambling backward into the garbage. The mugger stepped forward, raising his stone-bladed arms, taking a heavy, boxer's stance. 

"Come on then, greenie. Let's see what you—"

The mugger didn't finish his sentence. He didn't even see Izuku move. 

Izuku didn't step forward; he teleported. The explosive contraction of his calf muscles shattered the pavement beneath him, propelling him the twenty feet in a fraction of a millisecond. 

Before the mugger’s brain could even process the sound of the cracking concrete, Izuku was standing directly inside his guard.

Target acquired, Izuku’s hyper-analyzing brain supplied automatically, breaking down the mugger's biology in real-time. Quirk: Dermal Lithification. The epidermis secretes calcium and silica to form a crude stone armor. High impact resistance. Low tensile flexibility. Weak points: joints, eyes, unprotected visceral cavity.

Izuku drove his right fist directly into the center of the man's rocky sternum. 

He didn't pull the punch. The chemical high demanded a full-output test. 

The impact was deafening. It sounded like an artillery shell hitting a bunker. The sheer kinetic transfer of Izuku's hyper-dense fist meeting the stone armor caused the air pressure in the alley to violently pop. 

The mugger’s stone armor didn't just break; it exploded into powder. 

The massive man’s eyes rolled back into his head instantly. The force of the blow lifted his three-hundred-pound frame completely off his feet, sending him rocketing backward through the air. He flew a full thirty feet down the alley before crashing into a brick wall, cratering the brickwork, and collapsing into a heap of broken limbs and shattered stone. 

He didn't twitch. He was out cold. 

Izuku stood in the center of the alley, his fist still extended. 

Silence rushed back in, broken only by the whimpering of the woman against the wall. 

Izuku looked at his knuckles. The skin was completely unbroken. He flexed his fingers. 

I did it, he thought, a wave of euphoric awe crashing over him. One punch. I beat a villain with a combat Quirk with one punch. I'm strong. I'm exactly like him.

He turned his head, a bright, manic smile stretching across his face, fully intending to look at the woman and offer her a hand up. He wanted to ask if she was okay. He wanted to feel the warmth of being a savior.

But the moment his eyes landed on the mugger's unconscious body, a violent, unnatural spasm racked Izuku’s brain. 

The synthetic adrenaline in his bloodstream wasn't a natural hormone. It didn't dissipate once the threat was neutralized. The Serum Alpha had effectively hijacked his amygdala, locking his brain into an infinite, escalating loop of fight-or-flight. There was no flight. There was only fight.

He's still breathing. 

The thought wasn't a tactical observation. It was an insult. The mugger had dared to challenge him, and the mugger was still breathing. 

Izuku’s smile twisted. The corners of his mouth stretched too wide, bearing his teeth in a feral, aggressive snarl. The glowing green veins on his neck pulsed violently, throbbing in time with his racing, overworked heart. 

He walked slowly toward the unconscious man. 

"W-Wait..." the woman whispered from the shadows, her voice trembling. "He's... he's knocked out. You got him."

Izuku didn't hear her. The roar of the chemicals was too loud. It was a deafening, intoxicating chorus demanding violence. 

He reached down, grabbing the mugger by the front of his torn jacket, and effortlessly hauled the massive man up, pinning him against the cratered brick wall with his left hand. The man’s head lolled uselessly to the side. 

He called you a freak.

Izuku drew his right fist back. 

He thinks he's better than you because he has a Quirk.

Izuku drove his fist into the man's unprotected jaw. The sickening CRUNCH of bone shattering echoed off the brick. The mugger’s head snapped violently to the side, blood and teeth spraying onto the pavement.

Izuku didn't stop. He couldn't stop. His arm pulled back again on pure, chemical-induced reflex.

Smash him.

CRACK. Another punch, this one burying into the man's ribs. The sound of ribs snapping like dry twigs was horrifying. 

Break him.

Izuku hit him again. And again. And again. His fist was a blur, a piston of raw, unadulterated hatred and chemical rage. He was no longer punishing a mugger; he was punishing Bakugo. He was punishing All Might. He was punishing the entire genetic lottery that had cast him aside as a defect. 

Blood splattered across Izuku’s bare chest, warm and crimson, stark against the glowing green veins. He was laughing now, a broken, hysterical sound that bubbled up through the raw carnage. 

"STOP! OH MY GOD, PLEASE STOP! YOU'RE KILLING HIM!"

The scream finally pierced the veil. 

Izuku’s fist froze in mid-air, inches away from the pulverized, bloody ruin of the mugger's face. 

He blinked. The red haze of aggression receded just enough for his analytical mind to claw its way back to the surface. 

He looked at his hand. It was drenched in blood. He looked at the man he was pinning against the wall. The mugger's face was unrecognizable. His jaw was detached, his nose flattened, his chest violently caved in. He was gurgling, choking on his own blood, hovering on the precipice of death.

Izuku gasped, dropping the man as if he had been burned. The heavy body slumped to the concrete like a sack of wet meat. 

"No..." Izuku whispered, his voice cracking, returning to its normal, high-pitched timbre. "No, no, no, I didn't... I was just stopping him. I didn't mean to..."

He spun around, looking at the victim. 

The woman wasn't looking at the mugger. She was looking at Izuku. She had pressed herself as far back into the corner of the alley as physically possible. Her hands were covering her mouth, her eyes wide with an absolute, paralyzing terror. She was shaking violently.

She wasn't looking at a hero. She was looking at a monster. 

"I'm... I'm a hero," Izuku stammered, taking a half-step toward her, raising a blood-soaked hand in a placating gesture. "I saved you."

The woman flinched violently, letting out a stifled sob. "Stay away from me! You... you're a psycho! You're a villain!"

The word hit Izuku harder than a punch from All Might. Villain. 

He looked down at his blood-stained hands, at his violently expanded chest, at the toxic, glowing veins throbbing under his skin. The terrifying euphoria evaporated, instantly replaced by a sickening, cold horror. He had built this serum to become a hero. But the chemicals had stripped away his humanity. He had enjoyed the violence. He had wanted to beat a helpless man to death. 

"I'm sorry," Izuku whispered, tears finally welling in his eyes, mixing with the sweat and soot on his face. "I'm so sorry."

He turned and bolted. He didn't use the rooftops this time. He just ran, sprinting blindly into the darkness of the city, desperate to put as much distance between himself and the horrific reality of what he had just done.

He ran for what felt like hours, though his hyper-accelerated brain knew it was only minutes. He stuck to the shadows, moving through abandoned train yards and industrial sectors, terrified of being seen. The wind was cold against his bare skin, but the internal furnace still raged. 

He found himself in an abandoned construction site near the river, surrounded by half-built concrete pillars and rusted scaffolding. 

He collapsed against a concrete pylon, sliding down to sit in the dirt. He brought his knees to his chest, wrapping his arms around his head. 

"It's unstable," he muttered, rocking back and forth. His analytical mind was violently trying to wrest control back from the lingering chemicals. "The myostatin inhibitor works, but the synthetic adrenaline is overwhelming the dopamine receptors. It triggers a violent, psychopathic break. I have to dial down the catalyst. I have to—"

Suddenly, Izuku’s heart stuttered. 

It wasn't a skip. It was a massive, violent halt. It felt as though a cold, iron hand had reached into his chest and squeezed his heart to a complete stop.

Izuku’s eyes widened. He grabbed his chest, letting out a sharp, choked gasp. 

Thud.......... Thud...........................

The erratic, agonizingly slow beats sent a wave of absolute ice through his veins. The violent heat that had been radiating from his body vanished instantly, replaced by a freezing, deathly cold. 

The thirty-minute timer had run out. 

Serum Alpha had fundamentally exhausted its fuel source. The synthetic chemicals in his bloodstream were rapidly degrading, breaking down into highly toxic waste products. 

And then, the Crash began.

"G-GAAAGHHH!" 

Izuku screamed, throwing his head back, his vocal cords tearing as a pain infinitely worse than the injection ripped through his body. 

The carbon nanotubes, the microscopic scaffolding that had bound his violently expanded muscle fibers together, suddenly detached. Without the chemical catalyst to sustain the cellular regeneration, the massive, hyper-dense muscles had no structural support. 

Gravity and baseline human biology violently reasserted themselves.

Izuku watched in absolute horror as his arms began to deflate. The massive, corded muscles visibly shrank, but they didn't just shrink—they collapsed. The rapid deflation tore the muscle fibers from the bone. It was the physical sensation of being flayed alive from the inside out. 

"H-Help! SOMEBODY!" he shrieked, thrashing in the dirt, his fingernails clawing uselessly at his own skin. 

POP. SNAP. 

He could hear his own capillaries and minor blood vessels bursting under the sudden, massive drop in blood pressure. The glowing green veins on his skin turned violently black, then ruptured beneath the epidermis, spreading ugly, sprawling bruises across his entire body in seconds. 

His vastly expanded skeletal structure—the micro-fractured bones that had healed thicker—were suddenly too large for his shrinking muscles to support. His joints dislocated simultaneously. His right shoulder popped out of its socket with a sickening crunch. His kneecaps shifted out of alignment. 

He fell onto his side in the dirt, convulsing violently. He couldn't breathe. His lungs, which had been artificially hyper-oxygenated, suddenly collapsed under the strain, violently expelling air. 

He rolled onto his stomach, gagging. His stomach convulsed, and he vomited. 

He didn't throw up food. He threw up a thick, viscous mixture of black blood, bile, and the fluorescent green chemical residue. It splattered onto the dirt, burning the dry grass like acid. He heaved again, and again, until there was nothing left but dry, agonizing spasms.

The pain was so profound, so absolute, that his brain began to shut down to protect him from the shock. His vision tunneled, the edges bleeding into black. The edges of the concrete pillars blurred. 

I'm dying, Izuku thought, his mind surprisingly clear amidst the agony. The cellular necrosis is cascading. The metabolic crash is shutting down my organs. I flew too close to the sun, and my wings are melting.

He lay there in the dirt, a pathetic, broken heap. His body had returned to its frail, scrawny baseline, but it was ruined. He was covered in sweat, dirt, vomit, and the blood of the man he had nearly killed. 

He closed his eyes, waiting for the final, merciful darkness. He waited for his heart to simply give out.

But it didn't. 

Thud-thud. Thud-thud. Thud-thud. 

His heart, though bruised and battered, stubbornly returned to a normal, weak human rhythm. The starfish-stem-cell extract—the regenerative stabilizer he had added at the last minute—had just barely enough residual power to repair the fatal internal hemorrhaging. It wasn't enough to stop the pain, and it wasn't enough to heal the torn muscles, but it was enough to keep him from bleeding to death internally.

Izuku opened his eyes. The world was still there. He was still alive.

"Damn it," he whispered, a tear of pure, unadulterated agony sliding down his bruised cheek.

He didn't want to be alive. The pain was too much. The memory of the monster he had been was too much.

But as he lay there, the cold, analytical part of his brain—the part that had driven him to create the serum in the first place—refused to yield. 

You survived, it whispered. The formula is viable. The raw output is Pro-Hero level. The psychological break is a chemical imbalance, not a moral failure. It can be fixed. The physical crash is a structural failure. It can be mitigated.

Izuku ground his teeth together. The metallic taste of blood filled his mouth. 

He reached out his left arm—his good arm—and dug his trembling fingers into the dirt. Slowly, agonizingly, he dragged his broken body forward. Every millimeter of movement sent shockwaves of blinding pain through his dislocated shoulder and torn muscles. 

He had to get home. He had to hide the evidence. He had a mother waiting for him. He had an Entrance Exam in exactly one week. 

"I won't... die here," Izuku wheezed, dragging himself an inch. "I won't... be a failure."

The journey back to the apartment was a blur of excruciating torture. It took him three hours to cross the distance he had covered in minutes just an hour prior. He dragged himself through the darkest alleys, hiding behind dumpsters every time a police siren wailed in the distance. He had to manually pop his right shoulder back into its socket in a dirty alleyway, biting down on a piece of trash to muffle his own agonizing scream. 

By the time he reached the back of his apartment building, the sun was threatening to rise, painting the sky in soft, mocking hues of pink and gold. 

He looked up at his broken third-story window. It looked impossibly high. 

You can't jump anymore, Deku, he mocked himself. 

He dragged himself to the rusted fire escape. He reached up, gripping the lowest rung with bloody, trembling fingers. He pulled. His torn muscles screamed in protest, threatening to give out completely. He ignored the pain. He weaponized it. He used the agony as fuel, dragging his broken body up the metal stairs, one agonizing step at a time. 

When he finally tumbled through the shattered window of his bedroom, he hit the floor like a corpse. 

The room was exactly as he had left it. The splintered remains of his oak desk. The shattered glass of the syringe. The lingering smell of ozone and chemicals. 

Izuku didn't have the strength to stand. He crawled across the wooden floor, dragging himself toward the full-length mirror. 

He propped himself up against the wall, staring at his reflection. 

The monster was gone. The god was gone. Staring back at him was Izuku Midoriya. He looked like a corpse. His skin was deathly pale, marred by massive, ugly purple and black bruises that covered his entire torso. His eyes were sunken, hollowed out by pain and exhaustion. His lips were split and crusted with dried blood.

He looked weaker than he ever had in his entire life. 

But as he stared into his own dead, exhausted eyes, a cold, unyielding spark ignited in the emerald irises. 

He had touched the sky. He had felt the power of a god. He knew what it felt like to be untouchable. And he knew the cost.

A single, raw injection is suicide, he thought, his mind already spinning into overdrive, analyzing the data of his own near-death experience. The body cannot handle the instantaneous cellular expansion, nor can it handle the instantaneous crash. The psychological break occurs because the brain is flooded with a massive, unfiltered dose of synthetic adrenaline all at once.

He let his head fall back against the wall, looking up at the ceiling. 

I need a regulator, he realized, the blueprints already drawing themselves in his mind. I need a mechanical system. Something that can micro-dose the serum into my bloodstream continuously, keeping the body in a state of controlled, low-level enhancement without triggering the psychological break. And I need a way to purge the toxins before the crash kills me.

He closed his eyes. The Entrance Exam was in seven days. He didn't have time to chemically re-engineer the entire formula. He would have to build a machine to control the monster he had created.

He would have to become part machine, part chemical nightmare, just to stand on the same stage as Bakugo and the others. 

"I can do it," Izuku whispered into the quiet, ruined room. "I have to do it."

He drifted into a dark, exhausted unconsciousness on the floor, surrounded by broken glass and the blueprints of his own destruction, entirely committed to the path of the volatile hero.

The human body is an engine. It consumes fuel, generates kinetic energy, and produces waste. For fourteen years, Izuku Midoriya’s engine had been a compact, low-output, profoundly unremarkable machine. 

Now, he was going to turn it into a supercharger. 

The seven days following the catastrophic test of Serum Alpha were a blur of agonizing physical recovery and manic, obsessive engineering. For the first forty-eight hours, Izuku could not walk. The cellular necrosis and severe muscle tearing had left him bedridden, trembling under a cold sweat while his mother, Inko, paced the apartment in a panic, convinced he had caught a severe strain of the flu. He lied through his teeth, blaming it on over-studying and a bad fever, swallowing fistfuls of over-the-counter painkillers that did absolutely nothing to dull the agony of his regenerating tissues.

But by day three, the starfish-stem-cell extract in his residual bloodstream had done its brutal work. He was healed. His muscles were tighter, denser, a permanent physical change wrought by the violent expansion and contraction, but they were stable.

He didn't have time to rest. The UA Entrance Exam was looming, a giant ticking clock in the back of his mind.

Sitting cross-legged on the floor of his bedroom, surrounded by a graveyard of electronic components, medical supplies, and stolen laboratory equipment, Izuku began to build his salvation.

A single, concentrated dose is fatal, he reviewed in his mind, his hands deftly stripping the casing off a miniature pneumatic pump he had salvaged from a high-end automated blood pressure cuff. The instantaneous chemical reaction causes catastrophic tissue expansion and psychological dissociation. But a continuous, diluted intravenous drip... that bypasses the shock. It creates a plateau of enhanced output.

He spent his dwindling funds on the dark web, paying exorbitant fees for overnight shipping. He acquired medical-grade silicone tubing, sterilized intravenous needles, a mechanized insulin pump, micro-valves, and a heavy-duty tactical harness made of Kevlar webbing. 

He didn't sleep. He built.

He reprogrammed the micro-controller of the insulin pump, bypassing its safety limits and syncing it to a custom rotary dial he stripped from an old stereo amplifier. He mounted the pump to the center of the Kevlar harness, designed to sit flush against his sternum. From the central reservoir—a reinforced, shatter-proof polymer flask that would hold the Serum Alpha—he ran two primary arterial lines. 

The engineering was the easy part. The biology was the nightmare.

On the night before the exam, Izuku stood shirtless in his bathroom. The harsh fluorescent light illuminated his pale skin, still faintly mottled with the fading yellow and purple bruises of his crash. 

He laid his creation on the bathroom counter. The Auto-Injector Harness. It looked like an instrument of torture, a tangle of black webbing, mechanical servos, and clear surgical tubing. 

"Okay," Izuku whispered, his voice trembling slightly. He picked up a bottle of rubbing alcohol and a cotton pad, vigorously scrubbing the skin below his left collarbone, directly over his subclavian vein. He did the same to his right side, and then to a spot just above his left hip, targeting a branch of the femoral artery for rapid systemic circulation. 

He strapped the heavy Kevlar harness onto his torso, tightening the buckles until the central pump pressed hard against his sternum. It was heavy, restrictive, but completely concealed once he put a shirt on.

Then came the ports.

Izuku picked up the first intravenous catheter. It wasn't a standard needle; it was a permanent, heavy-duty Teflon port designed for continuous dialysis, modified with a one-way locking valve. 

He looked at himself in the mirror. He gritted his teeth, placing a rolled-up washcloth between his jaws. 

With a swift, brutal motion, he drove the thick needle deep into the flesh beneath his collarbone. 

A muffled, agonizing groan tore through the washcloth. Tears involuntarily streamed down his face as the thick gauge pierced his muscle and found the vein. Blood welled up instantly, dark and stark against his pale skin. He forced his shaking hands to stay steady, securing the port with surgical adhesive tape and medical staples, completely ignoring the sterile protocols he had read about. He didn't have the luxury of an operating room. 

He repeated the process on the right side, and then, excruciatingly, near his hip. 

Panting, drenched in cold sweat, Izuku connected the silicone tubing from the central pump into the three dermal ports. 

He carefully unscrewed the central reservoir, retrieving a fresh, glowing green vial of Serum Alpha—stabilized, slightly diluted with a saline buffer, but just as volatile. He poured the heavy liquid into the pump's tank and sealed it.

He placed his hand on the stereo dial wired to his ribs. It had four settings, indicated by crude notches he had carved into the plastic. 

Position Zero: Closed.

Position One: Baseline Drip.

Position Two: Combat Output.

Position Three: Override/Maximum.

"Testing Position One," Izuku gasped, spitting the washcloth into the sink. 

He turned the dial one click. 

A mechanical whir-click-hiss echoed in the small bathroom. The miniature pneumatic pump engaged. Through the clear tubing, Izuku watched the glowing green fluid race upward, hit the valves, and push directly into his veins.

The reaction was instantaneous, but unlike his first time, it wasn't an explosion. It was a creeping, electric fire.

Izuku gripped the edges of the porcelain sink. His pupils dilated rapidly, swallowing his green irises. The veins along his arms and neck surfaced, glowing with a faint, toxic luminescence, but they didn't bulge grotesquely. 

He closed his eyes, bracing for the psychological break, waiting for the bloodlust to drown his thoughts. 

He waited. Ten seconds. Thirty seconds. A minute. 

His heart rate had elevated to 140 beats per minute. His body temperature spiked to 102 degrees. He felt an intense, buzzing energy, a restless need to move, but his mind... his mind was entirely his own. He looked at the soap dispenser. He didn't want to destroy it. He just analytically recognized that if he squeezed it, it would shatter. 

He looked back in the mirror. The monstrous, feral beast was gone. Staring back was a young man with glowing, hyper-focused eyes and a jaw set in iron determination. 

"It works," Izuku whispered. He squeezed the edge of the porcelain sink. With a sickening crunch, the thick ceramic cracked under his grip, snapping off in his hand like a dry biscuit. 

He felt no strain. He felt perfectly calibrated.

He clicked the dial back to Position Zero. The pump hissed, a secondary vacuum valve engaging, injecting a micro-dose of chemical coagulant and saline to flush the lines and prevent his blood from clotting in the tubes. The green glow faded from his skin.

He had tamed the monster. He had put a leash on God.

Izuku threw on a baggy, dark green tracksuit, entirely concealing the mechanical harness and the tubes feeding into his flesh. He walked back into his bedroom, looking at the UA informational pamphlet on his desk.

Tomorrow, he thought. Tomorrow, I show them what realistic looks like.

The morning sun over Musutafu was blindingly bright, casting long, dramatic shadows across the towering, H-shaped monolith that was UA High School. Hundreds of middle school students milled about the front gates, buzzing with nervous energy, comparing Quirks, and mentally preparing for the most difficult exam in the country.

Izuku Midoriya walked among them, a ghost in a sea of vibrant colors. 

Underneath his green tracksuit, the heavy Kevlar harness pressed tightly against his skin. The mechanical pump was dead silent, but he could feel the cold metal resting against his sternum. He kept his head down, ignoring the excited chatter. He wasn't here to make friends. He was here to execute a mathematical equation.

"Out of my way, Deku!" 

A heavy hand shoved Izuku's shoulder. Izuku stumbled slightly, turning to see Katsuki Bakugo striding past him, his hands shoved deep into his pockets, his red eyes glaring with their usual mix of arrogance and contempt. 

Izuku didn't flinch. A month ago, a week ago, he would have cowered. Now, he simply analyzed the biomechanics of Bakugo's shove. Poor weight distribution. Too much momentum carried in the upper body. If I had engaged the pump, I could have shattered his wrist on impact.

"Good morning, Katsuki," Izuku said, his voice terrifyingly calm, completely flat. 

Bakugo paused, glancing over his shoulder. A flicker of unease crossed his face—the same unease from their last encounter in the hallway. Deku wasn't stuttering. Deku wasn't crying. Deku was looking at him the way a mechanic looks at a faulty engine. 

"Whatever, Quirkless," Bakugo scoffed, turning away and marching toward the auditorium. "Don't get yourself killed today."

Izuku watched him go. Position Two will be more than enough to surpass his kinetic output, he noted mentally. 

As Izuku turned to follow, the toe of his red sneaker caught on an uneven paving stone. Baseline human clumsiness struck. He pitched forward, bracing for the embarrassment of a faceplant. 

Suddenly, he stopped mid-air. 

"Are you okay?" a bright, cheerful voice asked. 

Izuku opened his eyes. He was floating an inch above the ground. He looked to his right. A girl with a round face, rosy cheeks, and short brown hair had tapped his shoulder. 

"It's my Quirk! Sorry for using it without asking, but it'd be bad luck if you fell right before the exam, right?" She smiled, pressing her fingers together. "Release!"

Izuku dropped the one inch to the pavement, landing lightly. 

The hero fanboy deeply buried inside him felt a flush of heat rise to his cheeks. A girl! I'm talking to a girl! But the analytical, cold-blooded scientist instantly overrode the emotion. Zero-gravity Quirk. Contact-based. Tactile telekinesis manipulating localized graviton fields. Extremely useful for rescue, highly vulnerable in ranged combat.

"Thank you," Izuku said, his voice polite but distant. He bowed slightly. "I appreciate the intervention. Good luck on your exam."

Before she could introduce herself, Izuku turned and walked away, his posture rigid. Uraraka blinked, slightly taken aback by the intense, almost robotic coldness of the boy, but she quickly shook it off, hurrying toward the doors.

Inside the massive auditorium, Pro Hero Present Mic stood on stage, screaming into a microphone, explaining the rules of the practical exam. It was a point-based system. Three types of villain robots—one, two, and three points respectively. Destroy them to rack up a score. Avoid the massive Zero Pointer obstacle. 

Izuku sat in the dark, tuning out the theatrics. He pulled a small notebook from his pocket, jotting down quick calculations. 

Urban environment simulation. Target: robotic constructs. Armor composition: likely standard industrial steel alloy or reinforced carbon-fiber plating. Vulnerabilities: joints, optical sensors, internal power supply.

He reached under his jacket, slipping his hand through a slit he had purposefully cut in his shirt, and rested his fingers on the stereo dial on his chest. 

When the briefing ended, the examinees were herded onto buses and transported to the various massive replica cities on the UA campus. Izuku found himself standing before the towering metal gates of Battle Center B. He was surrounded by dozens of other applicants, all doing stretches, psyching themselves up, or showing off their Quirks. 

Izuku just stood completely still, his head bowed, his eyes closed. 

"Right, let's start!" Present Mic's voice boomed from the loudspeakers. "What's wrong? There are no countdowns in real battles! Run, run, run!"

The massive gates began to groan open. 

Before the metal doors had even parted a full three feet, Izuku moved. 

His hand flicked the dial under his shirt. 

Click. Click. 

Position Two: Combat Output.

The mechanical pump hummed to life against his sternum. The valves snapped open. A concentrated, heavily calculated dose of Serum Alpha flooded his subclavian and femoral arteries, racing directly toward his heart. 

THUD-THUD.

The transformation was instantaneous. Beneath his tracksuit, Izuku’s muscles expanded violently, filling out the baggy fabric until it stretched taut over corded, dense tissue. The toxic green veins surfaced along his neck and the backs of his hands, pulsing with a vibrant, unnatural light. His body temperature spiked, vaporizing his sweat into a thin mist that hung around his shoulders.

The psychological rush hit him—a massive spike of aggression, a chemical demand for violence—but the micro-dose plateau held. He didn't lose his mind. He just lost his fear.

Izuku shot forward like a bullet from a gun, blurring past the other examinees, leaving a small crater in the concrete where he had been standing. 

"Whoa! Did you see that guy?!" an applicant yelled. 

Izuku was already fifty yards deep into the fake city. 

A One-Pointer robot rolled out from a side street, its single red optic locking onto him. "Target acquired," it droned mechanically, raising a blunt, hydraulic appendage. 

Izuku didn't break stride. His hyper-accelerated brain mapped the robot's structure in a millisecond. 

He launched himself into the air, clearing the robot's fifteen-foot height with absolute ease. As he descended, he twisted his body, bringing his right heel down in a devastating axe kick, aimed directly at the seam connecting the robot's chassis to its head. 

The impact sounded like a car crash. 

The hyper-dense bone of his heel, backed by chemically enhanced muscle and massive kinetic force, sheared straight through the robot's armor. The One-Pointer's head crumpled inward, sparks violently showering the pavement as its internal circuitry was pulverized. It exploded in a burst of black smoke, collapsing into a heap of scrap metal. 

Izuku landed lightly, the shockwave of his landing cracking the asphalt. 

One point.

He didn't pause to celebrate. He didn't pose. He just sprinted toward the next intersection. 

For the next ten minutes, Izuku Midoriya was a machine of absolute, terrifying efficiency. He moved with a brutal, mathematical precision. He didn't use flashy martial arts; he used raw, undeniable physics. 

A Two-Pointer lunged at him from an alleyway. Izuku ducked beneath its swinging arm, dug his fingers—now possessing the grip strength of an industrial vice—into the robot's knee joint, and simply ripped the hydraulic piston out of its socket. The robot toppled, and Izuku crushed its central processor with a casual stomp. 

Three points.

Three Three-Pointers cornered him in a plaza, firing non-lethal, high-velocity rubber missiles. 

Izuku’s expanded auditory canals registered the firing mechanisms before the projectiles even left the barrels. Time seemed to crawl. He sidestepped the first missile, caught the second one perfectly in his hand, spinning with the momentum to bleed off the kinetic energy, and hurled it right back at the third robot. The rubber missile struck the robot's optical sensor with enough force to shatter the reinforced glass, blinding it. 

Izuku closed the distance, grabbed the blinded robot by its tread-guards, and physically lifted the two-ton machine over his head. He threw it into the other two robots, a catastrophic collision of metal and oil that leveled the entire squad. 

Twelve points.

Up in the observation room, the UA teachers watched the myriad of screens, monitoring the applicants. 

"We have a strong crop this year," Midnight purred, tapping a clipboard. "Look at the explosion boy in Area A. Such raw destructive power."

"The girl with the gravity Quirk in Area B is utilizing excellent situational awareness," Snipe added. 

"But who is that?" 

All eyes turned to a center screen. Pro Hero Eraserhead—Shota Aizawa—leaned forward, his dark, baggy eyes narrowing as he watched the green-haired boy on monitor 4B. 

The kid wasn't just destroying robots; he was dismantling them with terrifying, clinical brutality. On the screen, Izuku punched clean through the torso of a Two-Pointer, ripping out a handful of wires to shut it down, completely unbothered by the jagged metal scraping against his bare arms. 

"Izuku Midoriya," Principal Nezu squeaked, flipping through a file. "Registered Quirk: None. Though he updated his application yesterday, claiming a late-blooming physical mutation."

"That's not a mutation," Aizawa muttered, his eyes tracking Izuku's blurring movements. "Look at his face. Look at the veins on his neck. His body temperature is registering absurdly high on the thermals. He's operating in a state of continuous physiological overdrive."

"A strength enhancement Quirk?" All Might, standing in the back in his deflated, skeletal form, watched the screen with a mixture of awe and deep, gnawing guilt. Is that the boy from the roof? He... he had a Quirk all along? Why did he ask me if he could be a hero without one?

"Perhaps," Aizawa said, pulling his capture weapon tighter around his neck. "But something feels... artificial about it."

Down in the fake city, the physical toll was beginning to catch up with Izuku.

Thirty-six points, Izuku thought, leaning against a brick wall, his chest heaving violently. 

Underneath the tracksuit, his skin felt like it was on fire. The Serum Alpha was a toxic catalyst, and while the micro-dosing prevented a catastrophic psychological break, the chemical byproducts were building up in his bloodstream. His muscles were throbbing, the carbon-nanotube bonds vibrating under the immense strain. 

The pump on his chest clicked, injecting a micro-dose of saline to cool the lines, but it wasn't enough. He was pushing his luck. The human body wasn't meant to run at 300% capacity for this long. 

He reached under his shirt, preparing to dial down to Position One to let his liver filter out some of the toxicity. He had enough points to pass. He could survive. 

Suddenly, the ground beneath his feet violently shook. 

It wasn't a tremor; it was an earthquake. The brick wall he was leaning against cracked, dust showering down on him. 

Izuku pushed himself off the wall, looking down the main avenue. 

The buildings at the far end of the street were exploding. Massive chunks of concrete and steel rained down as a monolithic, colossal shadow eclipsed the sun. 

The Zero Pointer. 

It was the size of a skyscraper, a terrifying behemoth of military-grade armor and crushing treads. Its singular, massive optic glowed an angry, apocalyptic red. It raised an arm the size of a city block and slammed it down, obliterating an entire row of fake office buildings. The resulting shockwave sent a hurricane of dust and debris ripping through the streets.

The examinees, who had been confidently fighting moments before, shattered into a blind panic. 

"Run! It's the obstacle!" someone screamed. 

Dozens of teenagers bolted past Izuku, their faces pale with terror, abandoning their fights to escape the mechanical titan. 

Izuku stood frozen. His analytical mind rapidly processed the threat level. Height: approximately 100 meters. Weight: thousands of tons. Armor: impregnable to current output. Threat level: Absolute. Recommendation: Evacuate.

He turned to run, to follow the logic. 

"Ow!"

The cry was small, almost entirely drowned out by the grinding gears of the Zero Pointer, but Izuku’s enhanced auditory canals caught it. 

He stopped. He turned his head. 

Forty yards away, trapped beneath a massive slab of concrete debris that had been kicked up by the robot's treads, was the brown-haired girl. Uraraka. Her leg was pinned. She was struggling wildly, using her gravity Quirk on the rock, but it was too massive, wedged awkwardly against the pavement. 

The Zero Pointer was rolling directly toward her, completely indifferent to the human obstacle in its path. 

She's going to die, Izuku realized, his heart skipping a beat. 

The examinees were gone. He was the only one left. 

The hero fanboy screamed to move. The cold, logical scientist coldly calculated that engaging a target of that mass would require a kinetic output that his current baseline could not achieve. Position Two was not enough to dent that armor. 

If I use Position Two, I die with her, Izuku thought, his eyes wide. 

He looked down at his chest. He could feel the dial pressing against his sternum. 

Position Three. Override. Maximum Output.

He remembered the alleyway. He remembered the unhinged, psychopathic rage, the blinding power, and the horrific, body-shattering crash that followed. If he fully opened the pump's valves, removing the restrictors and flooding his heart with an unfiltered tidal wave of Serum Alpha, he would achieve the strength of a god for approximately sixty seconds. 

And then, his engine would blow out. The sheer volume of the chemical catalyst would cook his cells, shatter his bones under his own torque, and likely kill him before the robotic treads even reached him.

The Zero Pointer's treads ground forward, closing the distance to twenty yards. Uraraka looked up at the towering machine, tears streaming down her dirty face, bracing for the end. 

Izuku Midoriya didn't think about All Might. He didn't think about Bakugo. He didn't think about being a hero. 

He just thought about the girl who had stopped him from falling. 

"Equation updated," Izuku snarled, his voice dropping into that terrifying, demonic register. 

He reached through the slit in his shirt. He grabbed the dial. 

He twisted it all the way to the right until it clicked violently against the plastic stopper. 

Position Three. Maximum.

Underneath his shirt, the pneumatic pump whined like a jet engine spinning up. The safety valves forcefully snapped open. 

Izuku didn't just feel the injection this time; he heard it. The rush of fluid into his veins sounded like a rushing waterfall. 

THUMP-THUMP. 

His heart violently seized, expanding painfully in his chest before hammering back with the force of a piledriver. 

"G-GAAAH!" Izuku roared, throwing his head back to the sky. 

The transformation was horrific. The baggy green tracksuit tore at the seams as his muscle mass violently, exponentially exploded. The toxic green veins didn't just surface; they bulged grotesquely, mapping his entire body in blinding, radioactive emerald. The heat radiating off his body was so intense it instantly vaporized the moisture on the pavement beneath him, engulfing him in a localized cloud of hissing steam. 

His eyes snapped open. The pupils were completely gone, his irises burning like green supernovas amidst an ocean of blood-red sclera. 

The psychological break hit him like a physical blow. The world tinted red. The analytical, calculating Izuku Midoriya was brutally suppressed, shoved into the backseat of his own mind. The monster had the wheel. And the monster was looking at the biggest piece of prey it had ever seen. 

The Zero Pointer raised its massive foot to crush Uraraka. 

Izuku crouched. The concrete beneath his feet didn't just crack; it violently imploded, creating a crater ten feet wide. 

SMASH.

He broke the sound barrier on takeoff. A localized sonic boom echoed through the fake city, shattering the glass of every remaining window in a three-block radius. 

Izuku rocketed upward, a streak of green lightning cutting through the dust. He bypassed the falling debris, ascending vertically fifty, eighty, a hundred feet into the air. 

He crested the height of the Zero Pointer’s colossal head. 

Time froze. In the observation room, Aizawa, All Might, and the rest of the faculty watched the screen in stunned, absolute silence. 

Hovering in the air, Izuku pulled his right arm back. 

The muscles in his arm were visibly vibrating, swelling to a grotesque size. The carbon nanotubes were failing, snapping under the sheer, unadulterated force of the chemical catalyst. He could feel his bicep tearing apart from the inside, his humerus micro-fracturing under the agonizing pressure. 

He didn't care. The monster only cared about destruction. 

"DIE!" Izuku roared, a terrifying, inhuman sound that echoed across the entire facility. 

He drove his fist forward. 

He didn't hit the robot's armor. He hit the air in front of the robot. 

The kinetic transfer was so massive, so incomprehensibly violent, that it literally weaponized the air pressure. A concentrated shockwave, visible to the naked eye as a rippling distortion in the atmosphere, erupted from his fist. 

The shockwave slammed into the center of the Zero Pointer's face. 

The impregnable carbon-fiber armor didn't just dent; it vaporized. The sheer force of the blow caved the robot's head in entirely, traveling down its spine, blowing out its internal hydraulic lines and central battery core in a catastrophic, cascading explosion. 

The titan's head snapped backward with a sickening screech of tearing metal. The massive body went rigid, sparks geysering from its neck, before the entire hundred-story construct violently tilted backward and crashed to the earth, the impact registering on seismographs across the city. 

Up in the air, the triumph lasted exactly one millisecond. 

And then, Izuku's arm exploded. 

Not literally, but internally, the damage was catastrophic. The sheer torque of the punch, combined with the chemical necrosis of Serum Alpha, proved too much for human biology, augmented or not. 

His right humerus shattered into dozens of jagged splinters. His radius and ulna snapped cleanly in half, the jagged edge of bone tearing through his muscles and jutting out against the skin of his forearm. The heavily expanded muscle tissue in his right arm completely detached from the tendons, rolling up into a useless, agonizing ball of flayed meat beneath his skin. 

"AAAAAAAAGH!" Izuku shrieked, his mind violently snapping back to reality as the pain instantly overrode the chemical high. 

He was falling. He was a hundred feet in the air, his right arm dangling uselessly, his body completely spent, his heart misfiring erratically as the pump desperately tried to flush the toxic overload from his veins. 

He looked down. The ground was rushing up to meet him. 

My legs, he thought through the blinding haze of pain. I can use my legs to absorb the impact. 

He braced his legs, preparing to land. But his left leg, which had absorbed the majority of the takeoff torque, was chemically burnt out. As he braced, the femur simply buckled under the strain, snapping with a horrific crack. 

I'm going to die, Izuku realized, the wind roaring in his ears. I saved her, but I'm going to die. 

He closed his eyes, waiting for the splat. 

SLAP.

A soft hand struck his cheek. 

Suddenly, the terrifying sensation of falling vanished. Izuku opened his eyes. He was floating, weightless, mere inches above the jagged debris of the street. 

Uraraka was standing below him, her face bruised and covered in dust, her hands clasped tightly together. She had managed to free herself just as the robot fell, using the distraction to levitate the debris off her leg. She was panting heavily, looking up at him with wide, terrified, grateful eyes. 

"Release," she gasped, falling to her knees and dry-heaving from Quirk exhaustion. 

Izuku dropped the remaining few inches to the ground. 

He hit the concrete, and the world dissolved into a canvas of pure, unadulterated agony. 

He couldn't move. He lay on his back, staring up at the hazy blue sky. His right arm was a mangled, distorted mess, leaking a dark, viscous mixture of black blood and glowing green serum onto the pavement. His left leg was bent at a completely unnatural angle. 

Under his torn shirt, the pump was whining a high-pitched, desperate alarm. Whir-click-hiss. Whir-click-hiss. It was frantically pumping saline and coagulant into his system, trying to stave off the fatal crash, but the lines were clogged with his thickened, toxic blood. 

Turn it off, his brain screamed. If you don't turn it off, it's going to pump an air embolism into your heart.

With his good left hand, he agonizingly reached across his chest, his fingers slipping on his own sweat and blood. He found the dial. 

He twisted it back to Position Zero. 

The pump hissed, the valves locking shut. The sudden, absolute deprivation of the Serum Alpha triggered the crash. 

Izuku began to convulse. Foam, laced with green, bubbled at the corners of his mouth. The massive muscles deflated instantly, leaving him looking like a starved, beaten corpse. The pain was so intense his brain couldn't process it; it felt like he was burning alive on a molecular level. 

Footsteps rushed toward him. The other examinees were gathering around, staring in absolute horror at the broken, bleeding boy who had just annihilated a mechanical god. 

"Is he... is he alive?" someone whispered. 

"Look at his arm. It's completely destroyed."

"Step aside, step aside!" a sharp, commanding voice broke through the crowd. 

An elderly woman in a doctor's coat and a syringe-shaped walking stick hurried forward. Recovery Girl, UA’s premier medical professional. 

She knelt beside Izuku, her eyes narrowing as she took in the horrific extent of his injuries. "Good heavens, boy. You've pulverized your own skeletal structure." 

She leaned down, puckering her lips. Her Quirk, Heal, worked by artificially stimulating the body's natural cellular regeneration, using the patient's own stamina to rapidly heal injuries. 

She kissed Izuku’s forehead. 

The reaction was immediate, and catastrophic. 

"GAAAAAAAH!" 

Izuku’s eyes snapped open, a scream of pure, unfiltered torture ripping from his throat. He thrashed violently, his good arm gripping the concrete so hard his fingernails tore off. 

Recovery Girl stumbled back, her eyes wide with shock. 

His cells... she realized, her medical expertise instantly identifying the horrifying anomaly. 

When her Quirk activated, it forced his cells to divide and heal. But Izuku’s cells were entirely soaked in the toxic, necrotic residue of Serum Alpha. By forcing them to divide, Recovery Girl hadn't healed him; she had hyper-accelerated the chemical burn. She was literally cooking him alive from the inside out. 

"Stop!" Izuku choked out, blood spilling over his lips, his hand clutching his chest where the hidden harness dug into his flesh. "D-Don't... don't use your Quirk... it burns..." 

Recovery Girl stared at the boy. She looked at the strange, unnatural glow of the blackish-green blood pooling around his shattered arm. She looked at his chest, noticing the faint, rectangular outline of machinery hidden beneath his torn shirt, and the surgical tubing pressing against his collarbone. 

She had seen underground fighters. She had treated villains high on Trigger. But this... this was something entirely new, and entirely terrifying. 

"Bring a stretcher! Now!" she barked at the automated medical robots rolling onto the scene. 

She leaned down, her face inches from Izuku’s, her voice dropping to a harsh, grave whisper meant only for his ears. 

"I don't know what you've put in your veins, boy," she whispered, her eyes filled with a mixture of pity and severe reprimand. "But this isn't a Quirk. You are rotting from the inside out. If you ever push yourself like this again, there won't be a body left for me to bury."

Izuku looked up at her through half-lidded, bloodshot eyes. He couldn't speak. He could only listen to the erratic, weak thump-thump of his failing heart, a grim reminder that he had survived the battle, but the war against his own body had only just begun. 

As the darkness finally rose to claim him, pulling him into a deep, merciful unconsciousness, the last thing Izuku Midoriya felt was the cold, unyielding metal of the pump resting against his ribs. 

His engine was broken. But he had passed the test.

The letter from U.A. High School did not bring tears of joy to the Midoriya household. It brought a heavy, suffocating silence.

Izuku sat on the edge of his bed, his right arm bound in a heavy, rigid polymer cast, suspended in a sling. His left leg was braced in carbon-fiber splints. His skin still held the sallow, grayish tint of someone who had recently danced on the very edge of multiple organ failure. On the desk in front of him, a small metal disc projected a high-definition hologram of All Might.

“You passed the written exam with flying colors! And in the practical, you scored an astonishing seventy-four rescue points! Izuku Midoriya... this is your Hero Academia!”

The hologram clicked off, leaving the dark room illuminated only by the faint, clinical glow of the computer monitor where Izuku had been running chemical simulations. 

He had done it. He had achieved the impossible. He had defied the gods of genetics, defied the Symbol of Peace, and forced his way into the most prestigious hero course on the planet. But as he stared at the blank metal disc, he didn't feel victorious. He felt the crushing, infinite weight of what came next. 

He was entirely, horrifyingly Quirkless. He had no genetic safety net. U.A. High was an institution designed to hone and push superhuman biology to its absolute limits. If Izuku wanted to survive the next three years—let alone graduate and become a Pro Hero—he couldn't just rely on a massive, suicidal injection of Serum Alpha whenever things got tough. 

He needed stability. He needed endurance. He needed Serum Beta.

Over the next three weeks, while his shattered bones knitted themselves back together with excruciating slowness, Izuku transformed his chemical synthesis process. 

Serum Alpha was a blunt instrument. It was a sledgehammer of raw synthetic adrenaline, myostatin inhibitors, and liquid fullerenes. It gave him the power to shatter a skyscraper, but the metabolic crash was fatal. For everyday use, for the grueling curriculum of U.A., he needed a formula that offered a lower, sustained plateau of enhancement without the catastrophic cellular necrosis. 

Izuku theorized that the core issue with Alpha was the synthetic adrenaline—it burned too hot, triggering the psychological break and forcing the heart into critical overdrive. So, he synthesized a new catalyst. He replaced the raw synthetic adrenaline with a complex cocktail of synthesized norepinephrine and modified neuro-peptides derived from a black-market pharmaceutical intended for narcolepsy patients. 

The resulting liquid was no longer a glowing, radioactive emerald. Serum Beta was a dark, viscous, almost oily green. It looked like toxic sludge. 

It didn't offer the explosive, god-like output of Alpha. Instead, it provided a massive, stable increase to his baseline muscle density, reflex speed, and pain tolerance, lasting up to four hours per dose. 

But the cost was in his head. 

To maintain the physical plateau without tearing his muscles apart, Serum Beta had to drastically elevate his blood pressure and manipulate his central nervous system to ignore the natural pain signals his body was sending. The result was severe, agonizing cranial pressure. 

Izuku had spent the last week before school testing the Beta strain. The physical results were flawless; he could lift a car and run a four-minute mile without breaking a sweat. But every time the serum was in his veins, it felt like someone was driving a rusted railroad spike directly into his temples. He suffered through blinding ocular migraines, ringing ears, and spontaneous, heavy nosebleeds. 

Worse, to make it viable for school, he had to ditch the bulky, obvious chest pump. He redesigned his delivery system into a sleek, low-profile auto-injector. It was a flat, titanium-cased dermal patch the size of a deck of cards, surgically taped to the small of his back, right over his spine. It held enough Beta for a standard school day, releasing micro-doses directly into his central nervous system via a capillary tap. 

He was walking into U.A. High School as a ticking time bomb.

The first day of U.A. felt like stepping into an alien world. The massive, towering corridors, the oversized doors, the sheer scale of the architecture—it was all designed for giants. 

Izuku navigated the halls of the school with the mechanical precision of a soldier in hostile territory. His U.A. uniform was tailored slightly loose to hide the sudden, dense muscle mass he had acquired, as well as the heavy bandaging still wrapped around his right forearm. 

He found the towering door marked 1-A and stepped inside.

The classroom was already buzzing with activity. To his left, the tall, blue-haired boy from the entrance exam—Tenya Iida—was rigidly chopping his arms through the air, loudly lecturing Katsuki Bakugo about having his feet on the desk. 

Bakugo was leaning back, his red eyes narrowed in absolute defiance, a cruel smirk playing on his lips. 

Izuku paused in the doorway. His emerald eyes, ringed with faint, dark shadows from a lack of sleep and the lingering withdrawal of his morning dose, swept the room. His hyper-analytical mind instantly categorized everyone. 

Engine legs. Multi-appendage mutation. Zero-gravity tactile telekinesis. Avian physiology. 

He didn't see classmates. He saw biological variables. He saw Quirks that nature had handed out for free, while he had bled and broken his own bones to stand in this room. A cold, detached apathy settled over him.

"Deku." 

Bakugo’s voice cut through the chatter. The explosive boy dropped his feet from the desk, his crimson eyes locking onto Izuku. The arrogant smirk vanished, replaced by a deep, hostile suspicion. Bakugo hadn't seen Izuku since the entrance exam, but he had heard the rumors. The kid who blew away the Zero Pointer. 

"Katsuki," Izuku replied, his voice completely flat, lacking the stuttering fear that had defined his entire life. 

Bakugo stood up, marching across the classroom until he was chest-to-chest with Izuku. "I don't know what kind of trick you pulled at the exam," Bakugo hissed, small explosions popping like firecrackers in his palms, filling the air with the smell of burnt sugar. "You’ve been Quirkless your whole damn life. You’re hiding something. And if you think you can look down on me with some fake, borrowed power, I'll kill you."

Izuku didn't flinch. He didn't blink. The dermal patch on his spine recognized the sudden spike in his cortisol levels and automatically released a microscopic fraction of a milliliter of Serum Beta into his bloodstream. 

A sudden, sharp spike of pain pierced behind Izuku's eyes, immediately followed by a wave of cold, absolute focus. His pupils dilated slightly.

"My power is my own, Katsuki," Izuku said softly, his voice devoid of any emotion. "I built it. If you want to test it against yours, you are welcome to try. But I promise you, the math will not be in your favor."

Bakugo’s eyes widened slightly. The sheer, chilling confidence in Deku's voice was unnatural. It wasn't bravery; it was the cold certainty of a scientist stating a physical law.

Before Bakugo could erupt, a tired, muffled voice came from the floor.

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

The entire class froze. Lying on the floor in a bright yellow sleeping bag, drinking from a juice pouch, was a haggard, unkempt man. He looked more like a vagrant than a teacher. He unzipped the sleeping bag and stood up, unwinding a thick, grey capture scarf from around his neck. 

"I'm Shota Aizawa. Your homeroom teacher."

Aizawa’s dark, sunken eyes scanned the room, lingering on Bakugo, then on Izuku. Izuku felt a sudden chill run down his spine. Eraserhead, his mind supplied instantly. Underground Pro Hero. Quirk: Erasure. He can temporarily neutralize a target's Quirk Factor by looking at them.

"Put these on and head out to the training field," Aizawa ordered, dropping a stack of blue and white P.E. uniforms onto the front desk. "We're not wasting time on orientation. We're doing a Quirk Apprehension Test."

The sun beat down on the sprawling, immaculate dirt of the U.A. physical training field. Class 1-A stood in a cluster, wearing their P.E. uniforms. 

Izuku stood slightly apart from the group. His head was pounding. A localized, rhythmic throbbing hammered against his left temple. Serum Beta was circulating through his system, maintaining his dense, heavy muscle mass, but the cranial pressure was mounting. He kept his face entirely passive, masking the agony. 

Aizawa stood before them with a digital tablet. "Bakugo. 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." Aizawa tossed him a baseball. 

Bakugo stepped into the pitcher's circle. He stretched his arm, a feral grin spreading across his face. He wound up, his palm igniting. "DIE!" he roared, throwing the ball with a massive, localized explosion that sent a shockwave across the field. 

The ball rocketed into the sky, leaving a trail of black smoke. Aizawa checked his device. "705.2 meters."

The class erupted into cheers and gasps. "705 meters? That's insane!" "We actually get to use our Quirks! This looks like fun!"

Aizawa’s eyes darkened, the temperature of the air seeming to drop several degrees. 

"Fun?" Aizawa’s voice was low, carrying a dangerous edge. "You have three years to become heroes. You think it's going to be games and playtime? Idiots. Today, you'll compete in eight physical tests to gauge your potential. Whoever comes in last has no potential and will be expelled immediately."

Silence slammed into the students like a physical weight. Uraraka gasped, protesting that it was unfair. Aizawa shut her down with a brutal speech about natural disasters, villain attacks, and the inherent unfairness of the world. 

Izuku barely heard him. He was calculating. 

Expulsion. I cannot be expelled. The laboratory equipment at U.A., the support course... I need access to their resources to perfect the serum. If I am expelled, I lose everything.

He reached around to the small of his back, his fingers brushing against the fabric of his shirt, directly over the titanium pump taped to his spine. There was a microscopic button on the side of the device. Pressing it manually flushed a higher concentration of Serum Beta into his spinal column. 

He didn't press it yet. He needed to test his baseline against the rest of the class. 

The tests began. 

Test 1: 50-Meter Dash.

Izuku lined up against a blonde boy with a laser-navel Quirk. When the starting gun fired, Izuku engaged his muscles. The Beta serum was stable. He didn't shatter the concrete like he did against the Zero Pointer. Instead, his legs pumped with the raw, mechanical efficiency of a cheetah. He crossed the finish line in a blur.

“3.15 seconds,” the robotic voice announced. 

It was fast—incredibly fast—but Iida, using his engine legs, scored a 3.04. 

Test 2: Grip Strength.

Izuku gripped the digital dynamometer. He squeezed, feeling the carbon-nanotube scaffolding inside his forearms hold his expanding muscles tightly together. He applied steady, escalating pressure. The machine groaned. 

“415 kg.”

He placed it down gently. A massive, multi-armed boy named Shoji scored 540 kg. 

Test 3: Standing Long Jump.

Izuku cleared the sandbox easily, utilizing the heavy density of his leg muscles, but the frog-girl, Asui, and Bakugo both out-performed him using the specific mechanics of their Quirks. 

As the tests progressed, Aizawa stood on the sidelines, his dark eyes observing everything. He recorded the scores, but his attention kept drifting back to Midoriya. 

Something was wrong with the boy. 

Aizawa was an expert in reading body language and Quirk activation. When a student activated a Quirk, there was a tell. A shift in stance, a deep breath, a localized tension, a spark of energy in the eyes. It was the biological engine firing up.

Midoriya had no spark. 

When Midoriya ran, when he jumped, when he crushed the dynamometer, his face was a mask of cold, agonizing blankness. He moved like a machine—too precise, too clinical. And there were physical signs Aizawa couldn't ignore. The boy’s skin was flushed, radiating an unnatural amount of heat. The veins on his neck and forearms were distended, tinted an ugly, bruised shade of green. And every few minutes, Midoriya would subtly reach up and pinch the bridge of his nose, his eyes squeezed tightly shut, as if fighting off a crippling migraine.

He's in pain, Aizawa analyzed, narrowing his eyes. His body is fighting his own power. During the entrance exam, he shattered his own limbs with a single strike. Now, he's holding back, maintaining a high baseline, but the strain is visible. A self-destructive enhancement Quirk? Or...

Aizawa remembered the USJ files he had read on underground trigger rings. Is he using enhancers? No, the medical screening at U.A. is flawless. A drug would have shown up in his bloodwork. (Aizawa didn't know that Izuku had engineered his serum to bind directly to the hemoglobin, mimicking natural cellular byproducts to evade standard toxicology screens). 

Whatever his Quirk is, it's volatile, and he has no control over it, Aizawa decided. He's exactly the kind of liability that gets himself and his teammates killed.

Finally, they arrived at the Softball Throw. 

Izuku’s rank was currently sitting comfortably in the middle of the pack. He wouldn't be last. He didn't need to push it. 

But as Uraraka stepped into the circle and threw the ball—scoring an infinity mark by removing its gravity—Izuku felt a hot trickle of liquid slide down his philtrum. 

He raised his hand and wiped his upper lip. He looked at his fingers. 

Blood. 

The cranial pressure was reaching a critical mass. The Serum Beta was over-saturating his central nervous system. His capillaries were beginning to burst from the sustained hypertension. He quickly wiped the blood on the leg of his P.E. pants, praying nobody noticed. 

"Midoriya," Aizawa called out, his voice sharp. "You're up."

Izuku walked into the pitcher's circle. He stood there, holding the baseball. The headache was blinding now, a kaleidoscope of jagged red and black cutting across his vision. 

Just throw it, he told himself. A baseline throw will get you 100 meters. That's enough to pass.

He looked up. Aizawa was staring at him. The underground hero's eyes were cold, calculating, and entirely dismissive. 

“You have no potential,” Aizawa had said earlier. 

The words echoed in Izuku's mind, fusing perfectly with the ghosts of his past. You can't be a hero without a Quirk. Take a swan dive off the roof. You're a liability. 

A sudden, vicious surge of chemical anger flared in Izuku's chest. It was the Beta serum reacting to his rising heart rate, pushing the dark, psychopathic edge of his consciousness forward. 

I didn't break my body to be average, Izuku thought, his emerald eyes darkening, a feral intensity sharpening his features. I am a god in a laboratory. I will not be dismissed.

Izuku reached around to the small of his back. 

Click.

He pressed the manual override button on the dermal patch. 

A heavy, concentrated, unfiltered dose of Serum Beta shot directly into his spinal fluid. 

Izuku gasped, his back arching slightly. The agonizing headache vanished instantly, utterly drowned out by a roaring, apocalyptic wave of pure, synthetic dopamine and adrenaline. The world snapped into terrifying, high-definition clarity. The ugly green veins on his arms suddenly flared, glowing through his skin like radioactive wire. His muscle mass visibly swelled under the blue P.E. uniform, the fabric tearing slightly at the shoulders. 

Aizawa saw the physical shift. He saw the sudden, dangerous spike in the boy's kinetic potential. 

He's going to do it again, Aizawa realized, his blood running cold. He's going to use the same suicidal output from the entrance exam. He's going to blow his arm off to prove a point.

"No you don't," Aizawa snarled. 

Aizawa’s Quirk, Erasure, activated. His long, black hair defied gravity, rising into the air like a halo of shadows. His dark eyes glowed a piercing, brilliant crimson. He locked his gaze directly onto Izuku Midoriya. 

Erasure was a biological interrupt. It targeted the Quirk Factor—the specific genetic mutation located in the subject's DNA—and temporarily severed its connection to the nervous system, effectively turning the Quirk off. 

Aizawa stared at Izuku, waiting for the boy's swollen muscles to deflate, waiting for the glowing veins to recede, waiting for the power to vanish.

Izuku drew his arm back. 

The power didn't vanish. It escalated. 

Aizawa’s crimson eyes widened in absolute shock. What?! My Quirk... it's locked on. I can feel the connection. But it's not doing anything!

Aizawa didn't know the terrifying truth. He was trying to erase a Quirk Factor that simply did not exist. Izuku Midoriya was 100%, genetically, a baseline human. You cannot erase a Quirk from someone who doesn't have one. Aizawa’s Quirk was useless against chemistry. It was like trying to use an EMP to turn off a campfire. 

Izuku stepped forward, planting his left foot into the dirt. The ground spider-webbed beneath his sneaker. 

He swung his right arm. 

He didn't just throw the ball. He weaponized it. The heavy, hyper-dense muscles of his shoulder and chest contracted with the force of an industrial hydraulic press. 

BOOM.

A deafening, concussive crack echoed across the field, identical to the sound of a thunderbolt striking the earth. The air pressure violently displaced around Izuku, creating a visible, rippling shockwave that kicked up a massive cloud of dust, forcing the students behind him to cover their faces and brace against the wind. 

The baseball vanished. It literally broke the sound barrier upon leaving Izuku's fingertips, creating a localized sonic boom that rattled the windows of the main U.A. building miles away. The friction of the air ignited the synthetic leather of the ball, leaving a fleeting streak of orange fire in the sky before it disappeared into the stratosphere. 

Total silence descended on the training field. 

Slowly, the dust settled. 

Izuku stood in the pitcher's circle. His right arm was extended, steam rolling furiously off his skin. The sleeve of his P.E. uniform had been completely shredded by the concussive force of his own throw. But unlike the entrance exam, his arm wasn't broken. The Beta strain, combined with his body's forced adaptation over the last three weeks, had held his bones together. 

He was trembling violently, but he was whole. 

Aizawa stood paralyzed. His hair slowly fell back to his shoulders, the red glow fading from his eyes. He looked at the digital scanner in his hand. The screen was flashing a single number. 

1,214.6 meters.

Aizawa slowly looked up, staring at the boy. The sheer impossibility of what had just happened short-circuited the Pro Hero's seasoned mind. 

I erased him, Aizawa thought, a cold sweat breaking out on the back of his neck. I looked right at him. I engaged his Quirk Factor. And he still threw it with the force of a cruise missile.

The class erupted. 

"Over a kilometer?!" Kaminari shrieked, grabbing his head. 

"That was faster than a bullet! I couldn't even see it!" Sero yelled. 

Bakugo, however, wasn't cheering. He was standing completely rigid, his face pale, his eyes wide with a mixture of terror and absolute, murderous rage. 

"DEKU!" Bakugo roared, explosions violently detonating in both of his palms as he launched himself forward, sprinting directly at Izuku. "WHAT THE HELL WAS THAT?! YOU QUIRKLESS BASTARD, TELL ME HOW YOU DID THAT!"

Before Bakugo could cross the distance, Aizawa moved. 

The grey capture scarf lashed out like a striking viper, wrapping tightly around Bakugo’s torso and arms, pinning him in place. 

"Stand down, Bakugo," Aizawa commanded, his voice dark and strained. 

"Let me go! He's faking it! He's a Quirkless nobody!" Bakugo thrashed against the bindings, his red eyes burning with a furious, desperate denial. 

"I said, stand down." Aizawa activated his Quirk again, erasing Bakugo’s explosions. The blonde boy instantly went limp against the scarf, grinding his teeth in frustration. 

Aizawa released him, then turned his gaze back to Izuku. 

Izuku had slowly lowered his arm. The massive chemical rush was already beginning to recede, leaving behind an agonizing wave of physical exhaustion. Another stream of dark red blood trickled slowly from his left nostril, stark against his pale skin. He wiped it away with the back of his hand, his emerald eyes meeting Aizawa’s dark gaze. 

"Midoriya," Aizawa said softly, taking a step toward the boy. The rest of the class fell completely silent, sensing the immense tension radiating from their teacher. "Explain yourself."

"Explain what, sir?" Izuku replied, his voice terrifyingly calm, devoid of the exhaustion that was ripping his body apart. 

"My Quirk," Aizawa stated, his eyes narrowing to slits. "I activated Erasure before you threw that ball. I looked directly at you. And yet, your power didn't even flicker. Why?"

The class gasped. Murmurs broke out. Erasure didn't work? Is that even possible? What kind of Quirk is immune to Eraserhead?

Izuku’s hyper-analytical mind went into absolute overdrive. He knows. He knows it's not a standard Quirk. If I tell him the truth—that I am chemically augmenting myself with a synthesized bio-weapon—he will arrest me. He will hand me over to the police, and my life is over. I need a lie. A perfect, biological lie.

Izuku took a deep breath, steadying his violently trembling legs. 

"You couldn't erase it, Mr. Aizawa," Izuku said, raising his chin slightly, locking eyes with the Pro Hero, "because there's nothing to erase."

Aizawa stopped walking. "Clarify."

"My Quirk..." Izuku began, spinning the lie with the cold, detached precision of a sociopath, "It’s classified in my medical files as an anomalous physiological state. I call it Adrenaline Trigger."

Izuku pointed a finger to his own temple. "I don't possess a Quirk Factor. Not in the traditional sense. I don't have a genetic off-switch. My power is entirely hormonal and structural. Under extreme stress or conscious demand, my endocrine system floods my body with a hyper-concentrated, mutated strain of adrenaline, while my cellular structure instantaneously condenses to handle the kinetic output."

Izuku let his hand drop. He gestured to the shredded sleeve of his uniform, to the glowing, bruised veins on his arm. 

"It's not an ability, sir. It's a biological reaction. It's biology. Your Quirk targets the genetic factor that activates power. But you can't erase my adrenal glands. You can't erase my bone density. You can't turn off my biology any more than you can erase a mutant-type's extra arms."

Aizawa stared at him, his mind racing. 

A pure physical mutation, Aizawa thought, scrutinizing the boy's flushed skin, the bloody nose, the mechanical, pained way he moved. A hormonal anomaly that mimics a strength Quirk without a Quirk Factor. That would explain the excruciating physical toll. It explains the nosebleeds, the vascular distension, the lack of a 'spark'. His body is literally poisoning itself with its own adrenaline.

It made sense. It was biologically sound. It perfectly explained why Erasure had failed. 

But Aizawa’s gut—the instincts honed over a decade of fighting in the criminal underworld—screamed that the boy with the cold, dead emerald eyes was lying through his teeth. 

"A biological reaction," Aizawa repeated slowly. He stepped into Izuku’s personal space, towering over the boy. Aizawa leaned down, his face inches from Izuku’s, speaking so softly that only Izuku could hear. "You think you're clever, Midoriya. You think you've got this all figured out. But whatever this 'Adrenaline Trigger' is... it's destroying you. You’re bleeding from your face. You're trembling. You look like a junkie coming off a high."

Izuku’s heart hammered against his ribs, but his face remained a mask of stone. 

"I have it under control, sir," Izuku whispered back. 

"No, you don't," Aizawa countered, his dark eyes boring into Izuku's soul. "You're a liability. To yourself, and to this class. I'm going to watch you, Midoriya. Every move you make. And the second you slip, the second this 'biology' of yours puts another student in danger... I won't just expel you. I'll lock you away."

Aizawa pulled back, his expression returning to its bored, apathetic default. He turned to the rest of the class. 

"We're done here. Go change and head back to the classroom."

As the class began to disperse, buzzing with excited whispers and terrified glances in Izuku's direction, Izuku stood frozen in the dirt. 

He had survived the test. He hadn't come in last. But the victory felt like ash in his mouth. He had just painted a massive, glowing target on his own back. The smartest, most perceptive teacher at U.A. was onto him. 

And worse, the Serum Beta was crashing. 

Thirty minutes later. 

The locker rooms were empty. The rest of the boys had quickly changed and hurried back to class, eager to avoid the terrifying tension surrounding Midoriya and Bakugo. 

Izuku was alone in the furthest bathroom stall. 

He was sitting on the tiled floor, his knees pulled to his chest, his back pressed against the cold metal partition. He was shaking. He wasn't shivering from the cold; he was experiencing severe, violent neuromuscular tremors. 

His teeth chattered audibly, echoing in the quiet bathroom. 

The massive override dose he had injected for the ball throw had completely depleted the Beta reserves in his dermal patch. His central nervous system, which had been artificially elevated to superhuman levels, was plummeting back to a baseline it hadn't known in weeks. 

His brain felt like it was wrapped in barbed wire. A steady stream of blood dripped from his left nostril, spotting his white undershirt with crimson. The muscles in his shoulders and legs spasmed violently, cramping so hard it brought tears of agony to his eyes. 

"S-Stop... stop it..." Izuku whimpered, his hands gripping his own arms, trying to force his muscles to stop vibrating. 

It was withdrawal. Pure, unadulterated chemical withdrawal. His body had become entirely dependent on the toxic plateau of the Serum Beta. Without it, his nervous system was misfiring, sending phantom pain signals across every nerve ending he possessed. 

He couldn't go back to class like this. If Aizawa saw him shaking, saw him physically collapsing, the lie would fall apart. He would be sent to Recovery Girl, she would run a blood test, and she would find the synthetic peptides. 

He needed to stabilize. 

With agonizing slowness, Izuku reached into the deep pocket of his P.E. pants. His trembling fingers closed around a small, cylindrical object. 

He pulled it out. It was a tiny, glass ampoule, capped with a microscopic, spring-loaded needle. An emergency dose. 

He held it in his shaking hand, staring at the dark, oily green liquid sloshing inside. 

This was the serum that was killing him. It was destroying his brain chemistry, rupturing his blood vessels, and slowly alienating him from his own humanity. It had turned him into a cold, calculating liar. It had made him a monster. 

He hated it. He hated the color green. He hated the smell of the chemicals. He wanted to throw the vial against the tile wall and shatter it. He wanted to be Izuku Midoriya again. 

But as another violent tremor wracked his spine, making him gag on a wave of intense nausea, the cold, analytical scientist in his brain spoke up. 

If you don't take it, you fail. You become the Quirkless Deku again. Power requires sacrifice.

Izuku squeezed his eyes shut. A single tear escaped, cutting a path through the sweat and dirt on his cheek. 

He unbuttoned the top of his shirt, exposing the bruised, pale skin of his collarbone. He pressed the tip of the ampoule against his flesh. 

He pressed the release button. 

Hiss.

The micro-dose of Serum Beta injected directly into his bloodstream. 

Within three seconds, the violent tremors ceased. The blinding headache dulled to a manageable ache. His breathing steadied, and the agonizing cramps in his muscles released, replaced by a warm, familiar, toxic hum of power. 

Izuku slowly opened his eyes. The vulnerability, the pain, the humanity... it all washed away, suppressed beneath the heavy, synthetic blanket of the chemicals. 

He wiped the blood from his nose with a piece of toilet paper. He stood up, adjusting his uniform, ensuring the collar perfectly hid the injection site. He looked at his reflection in the polished metal of the stall door. His eyes were cold, green, and completely dead. 

He was stable. He was ready for class. 

He flushed the empty glass vial down the toilet, unlocked the stall door, and walked out of the bathroom, stepping further down the dark, spiraling path of his own creation.