Amid the oppressive silence of a military base hidden between forgotten valleys, there was a special wing — cold, isolated, and shrouded in an almost suffocating atmosphere of inhumanity. Within it, behind reinforced layers of steel, blast-proof glass, and surveillance sensors, lay a singular cell. And there, at the heart of the prison, was he: prisoner number 048.
His name was Derek.
He had black hair, cut roughly and unevenly, as if not by choice, but by protocol. The dark strands contrasted starkly with the pallor of his skin, which was marked by fresh scars and poorly healed bruises. His eyes, a deep crimson, shone with a disconcerting intensity — like live embers buried beneath the snow.
He wore the standard inmate uniform of the facility: a worn, stained orange jumpsuit, with the number 048 printed in white on the back and on the right side of the chest. Around his neck was a black metallic collar — a piece of advanced technology marked by circuit lines that pulsed red and blue. It was no mere accessory: it was a containment collar, equipped with inhibitors and shock systems capable of paralyzing an elephant with a single pulse.
'This isn't good…' Derek thought as he tried to move his arms and legs — a futile attempt. His limbs were restrained by four steel pillars anchored to the floor, ceiling, and sides, as if he were a weapon of mass destruction awaiting release.
"Dying was already enough... and now I reincarnate imprisoned? What god did I piss off in this life?"His thought came laced with sarcasm, mixed with revolt and mental exhaustion. He took a deep breath, trying to calm his mind, letting the air—though heavy and dense—help him regain some focus.
Even in that situation, Derek still had something no one there could take from him: his mind. With a bit of effort and the discipline acquired in his past life, he retreated within himself, entering what he called his "mental palace."An intimate and abstract space that took the form of his old bedroom — a nostalgic refuge with worn walls, old posters hanging, and a bed covered with wrinkled blue sheets. Slowly, he began to organize the inner chaos, moving memories, emotions, and ideas into their proper places. But not everything was where it should be.
One thing stood out from that carefully constructed environment.
A glow.
A presence.
A power.
One For All.
He felt it pulsing like a living flame in the corner of the mental room, set apart from everything else, like a legendary artifact that didn't entirely belong in that space. The power passed down from generation to generation with a singular purpose — to fight its absolute opposite: All For One.
Derek approached that presence, observing it with a mix of curiosity and resignation. He shook his head, forming an ironic smile.
'Funny… I always preferred All For One. So much more flexible, chaotic, with infinite possibilities.'
But the disappointment was short-lived. He knew that One For All was an extraordinary gift. A raw, noble power capable of feats that transcended imagination. It was versatile, grand… only, it carried a tremendous weight.
'Wish I could use it now... but without physical conditioning, my body would shatter like nachos after a bite.' He sighed again, frustrated. It was no use having a nuclear bomb in his chest if his body was nothing more than an eggshell.
Derek's gaze wandered around the cell, analyzing every detail of that inhospitable space. No bed. No sink. No toilet. Nothing. Just the cold metallic floor, the bare walls, and the constant surveillance of hidden cameras.
'This shouldn't even be called a cell... it's a containment box,' he thought, clenching his fists. "I'd rather break my entire arm than live like this."
The words slipped out in a hoarse murmur, more to himself than to anyone else. But at that moment, he heard footsteps—heavy, rhythmic, coming from the outer corridor. They echoed through the metallic structure like war drums.
The heavy cell door opened with a slow, mechanized creak. A man stepped in. Tall, broad-shouldered, wearing a military uniform impeccably fitted to his body. He wore an expression of disdain etched onto his face. The soldier's eyes landed on Derek as if he were a disease—a mistake that needed to be corrected.
"Let's go," he said coldly, without even attempting a more humane tone. "It's time for your experiment."
At the command, the pillars that had immobilized Derek began to retract, groaning with the metallic sound of ancient gears, freeing his arms and legs. However, before he could attempt any sudden movement, his hands were immediately locked in cuffs that covered his entire forearms—made of a dark, dense material with engravings and integrated sensors.
Derek remained silent, but his gaze stayed fixed on the soldier, as if silently saying: "I'm still here. And not for much longer like this."
As he was escorted through the cold, industrial corridors of the base, Derek kept his eyes sharp. His bare feet touched the metallic floor with each heavy step, the echo of his footsteps blending with the hum of fluorescent lights above. The walls were lined with dark steel, dotted with numbered plaques and safety warnings, all meticulously designed to intimidate. But what caught his attention the most were the cells along the way.
Or at least, what seemed like cells.
Some had reinforced glass windows; others were sealed with armored doors featuring small viewing slots. Behind a few, shadows moved — distorted humanoid forms, creatures that looked like they had crawled out of genetic nightmares. Others appeared to be just people... or almost. Derek narrowed his eyes, trying to detect a pattern, if there even was one. These weren't just prisoners. It looked more like a zoo of aberrations. A living lab.
'So I'm not the only one...' he thought, his stomach twisting at the idea of being just another lab rat.
That's when they reached a new sector. The doors opened to reveal a vast, circular space, surrounded by empty bleachers and high lights casting a raw brightness onto the center of the area.
An arena.
The soldier behind him didn't bother explaining. He simply pressed a button on his wristband, and Derek's shackles unlocked with a magnetic click, falling to the ground with a dull thud. Then, without ceremony, he shoved him forcefully into the central circle.
Derek stumbled two steps forward but remained standing, teeth clenched.
"Asshole..." he muttered under his breath, brushing off his shoulder with disdain.
That's when he heard another metal gate open, on the opposite side of the arena. His eyes quickly turned to the new figure emerging.
And what entered was not human.
It was a being with green-gray scaled skin that reflected the light like oily leather. Its eyes, thin and yellow, resembled a serpent's — cold, predatory. Its muscular body looked sculpted through pain and forced mutations, and it wore only a pair of orange pants identical to Derek's.
'Oh, fuck...' Derek thought, swallowing hard. 'An arena and a muscular guy with a reptile face? They're testing me. This is a show. Or an experiment. Maybe both.'
A voice echoed through the loudspeakers, harsh and emotionless:
"Mutants 048 and 021, begin combat. Only one may leave in full fighting condition. Begin."
Without hesitation, the serpent-man lunged forward like a beast in a frenzy, his feet pounding against the metallic floor with surprising force.
Derek didn't even have time to come up with a strategy. His instincts kicked in, and he crossed his arms in front of his body, forming an improvised guard at the exact moment the monster's fist collided with him.
BAAM!
The impact was brutal. He felt his feet lift off the ground before he was launched like a cannonball into the arena wall. The sound of dented metal and rattling bones echoed through the chamber.
"SHIT!" Derek shouted, sliding down the wall until he landed on his knees, gasping. His forearms throbbed, and a vivid redness had already begun to spread across his skin. He wasn't sure if it was a bruise or if he was about to lose sensation.
"Hurts like hell..." he muttered, rotating his shoulders with difficulty. "Looks like I'll have to use it sooner than I wanted…"
He knew he couldn't just stay on the defensive anymore. One For All wasn't a gentle power — it demanded presence, decisiveness. Activating it was actually simple, but it required emotional control and a clear mental image. For Derek, the chosen visualization was elegant and direct: he imagined a crystal goblet being slowly filled, the liquid — a glowing energy — being poured into it.
The energy moved.
It responded.
"You just gonna talk, or are you gonna fight?!" snarled the mutant, still standing at the center of the arena, impatient.
Derek rose slowly, brushing the dust from his uniform with one hand as he smiled sarcastically.
"Hold on, dimwit… unlike you…"
BOOM!
A sudden shockwave burst from his body, sweeping away the dust and violently pushing the opponent back. The ground cracked beneath his feet.
The serpent-man was hurled like a ragdoll, tumbling across the floor before staggering to his feet, dazed.
Derek now stood tall, one arm extended forward, wrapped in black lightning streaked with red veins. His eyes burned with fierce intensity, and the energy around him trembled, as if the very air was being torn apart.
"My power is far more destructive," he declared, his voice steady and dripping with disdain.
Even with his arms still aching, Derek was whole. Unlike previous reports of One For All users, his body withstood the pressure far better—perhaps due to his altered physiology since reincarnation, or maybe because of something yet unrevealed.
Lightning continued to dance around his body as he assumed a combat stance. His muscles were tense but not torn. The energy flowed like a river held back by the dam of his willpower.
Using One For All isn't hard, and it seems like my body can handle the damage at 20%, he thought, preparing for his next move. Full Cowling, when I saw it in the manga, the idea was just to spread the energy evenly instead of dumping it all in one spot. I wonder why Izuku Midoriya never thought of that from the start.
With a snap of his fingers and a defiant grin, Derek charged forward.
A blur of orange and black sliced through the air like lightning, and in an instant, Derek's fist collided with the serpent mutant's face.
Crack!
The sharp sound of impact echoed through the arena, but before the blow could fully land its devastation, the mutant instinctively leapt back, dodging at the last second. Derek's fist instead struck the wall behind—causing it to crack violently under the brute force.
"Tough luck for you… having me as your opponent," Derek said in a calm, almost bored tone, as he pulled his hand back from the now fractured wall.
The other replied with nothing but a fierce grunt—a guttural sound of pure hatred.
"Grr!"
The rage etched on the mutant's face drew an even wider grin from Derek, whose red eyes sparkled with amusement.
"That's it... show me more. I love watching people try."
The reptilian creature—or perhaps one with crocodile genes—lunged forward with all its might, leaping high, aiming a flying kick straight at Derek's chest. But it never got there.
At the exact moment of impact, Derek simply stretched out his arm and caught its heel mid-air, stopping the attack with a motion so casual it was like picking fruit off the ground.
"Are you stupid, or just way too brave?"
With a quick twist, Derek used the enemy's own momentum against him, flinging him in an arc through the air.
'Looks like I still remember a bit of martial arts,' he thought confidently, jumping right after.
He spun through the air with precision—as if combat instinct flowed as naturally as breathing—and landed a devastating kick to the mutant's stomach, launching him like a missile toward the arena floor.
BOOM!
Dust shot up, and a crater formed where there had once been only metallic ground. The impact made the bleachers tremble slightly.
Derek landed moments later, hands on his hips, wearing a carefree smile.
"Ha... What a shame. Looks like 20% is already too much for you," he said aloud, his eyes glowing with red and black electricity.
Then he casually turned toward one of the cameras installed in the corners of the arena. He knew he was being watched—tested, evaluated, maybe even underestimated.
"So... did you like what you saw?" he asked with a mocking smile, raising an eyebrow.
On the other side of the screens, the scientists watched in silence. Some clenched their teeth in anger at the provocation. Others exchanged uneasy glances. But all of them froze when they saw what he did next.
Derek reached for the metallic collar around his neck — the same one meant to restrain, track, and control his movements.
Without hesitation, he closed his hand around the collar.
Crack.
With a dry, final sound, the device was destroyed as if it were made of plastic.
"Well…" he said, lifting his gaze back to the camera. "With that confirmed... I hope you've got something stronger than this if you plan to stop me."
And then he stomped hard.
BOOM!
The entire floor shook. The base's structures vibrated. Lights flickered. And immediately, the camera feed was cut — either from a system failure or someone panicking.
Derek stood in the center of the arena, surrounded by smoke and sparks, before turning into a blur as he smashed through the arena wall.