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The sun hung low over the Musutafu skyline, casting long, skeletal shadows across the pavement, but Midoriya Izuku didn’t see the sunset. He didn’t see the vibrant oranges or the bruised purples of the sky. All he saw were the vectors of motion, the biological anomalies, and the latent energy signatures radiating from every passerby.
To the world, Izuku was a normal member of society]. He was the boy who sat in the back of the lecture hall, the one who always had a notebook open and a pen moving so fast it seemed to blur. His teachers praised his dedication; his peers ignored his muttering. They saw a student with a helpful, if somewhat obsessive, analysis quirk. They saw a scholar. They didn't see the predator hiding behind the green curls and the nervous smile.
Inside Izuku’s mind, the Hunger was screaming.
It had been seventy-two hours since his last ‘feeding.’ To anyone else, a feeding meant a meal, but to Izuku, it was the raw, unadulterated intake of complex information. His quirk wasn't just analysis; it was a gluttony for knowledge that bordered on the divine and the sinister. When he went too long without deconstructing a new quirk, the world began to fray at the edges. The sounds of the city became a cacophony of unanswered questions. The sight of a person using a quirk, even something as simple as a finger-lighting ability to find a keyhole, felt like a crumb tossed to a starving man.
He gripped his pen until his knuckles turned white. He was currently sitting in a crowded café, trying to maintain his mask of normalcy. Across from him, a girl was levitating her sugar cubes into her coffee.
‘Telekinesis? No. Molecular tethering?’ Izuku’s mind raced. ‘The cubes aren't wobbling. There’s a localized gravitational shift. Look at the surface of the coffee, the ripples are moving outward from the center of the cup, not the cube. She’s not lifting the sugar; she’s manipulating the air pressure beneath it to create a vacuum lift. Simple. Low output. Boring.’
He felt a surge of irritation. It wasn't enough. The Hunger wanted more than ‘boring.’ It wanted the mechanics of gods. It wanted to know how a man could turn his blood into fire without searing his own lungs. It wanted to know the exact threshold where a body’s cellular structure collapsed under the weight of a transformation quirk.
He stood up abruptly, his chair screeching against the floor. A few patrons looked up, but he gave them the ‘Izuku smile’, the one that was soft, apologetic, and perfectly curated to look harmless.
"Sorry," he whispered, his voice trembling with a hunger they couldn't possibly understand. "Just remembered an assignment."
He stepped out into the cool evening air, and the hunger hit him like a physical blow. His vision tunneled. The air felt heavy, saturated with the potential of thousands of quirks he hadn't yet cataloged. He began to walk, his pace quickening into a frantic stride. He wasn't looking for a fight; he was looking for a revelation.
He followed the sound of a distant explosion. Most people ran away from the sounds of combat, but Izuku ran toward them with a desperate, frantic energy. He slipped through an alleyway, his movements practiced and silent. He reached a perimeter established by the police. A villain with a Gigantification-variant quirk was causing havoc near a construction site.
Izuku didn’t look at the destruction. He didn’t look at the terrified civilians. He looked at the villain’s skin.
‘Epidermal thickening occurring at a rate of 400% per second,’ he noted mentally, his pen already flying across the page of a fresh notebook. ‘The caloric intake required for such a shift must be astronomical. Is he pulling mass from the atmosphere? No, look at the muscle density. It’s a conservation of mass quirk, he’s condensing his internal structure and then expanding the gaps between molecules. That means his bones are becoming porous. He’s vulnerable to high-frequency sonic vibrations.’
It was a start, but it wasn't a feast. The villain was a brute, his quirk a blunt instrument. Izuku needed something elegant.
Then, he saw it.
A Pro-Hero landed on a nearby rooftop. It was an underground hero Izuku hadn't seen in person before, Phase-Shift. The hero didn't use strength; he moved through solid objects.
Izuku’s heart hammered against his ribs. This. This was what he needed.
As Phase-Shift dove into the fray, Izuku didn't just watch; he dissected. He saw the way the hero’s body flickered. It wasn't just ‘passing through’ matter. It was a rhythmic oscillation. The hero was vibrating his atoms at a frequency that bypassed the atomic bonds of the structures around him.
‘How does he breathe while phased?’ Izuku wondered, the hunger in his mind turning into a roar. ‘Does he phase his lungs? If he phases his lungs, he can't exchange oxygen. He must be holding his breath. No, look at the throat. The larynx is still solid. He’s phasing everything EXCEPT his respiratory system. But if his lungs are solid, how does he move through a wall without them being ripped out?’
The realization hit him like a lightning bolt. ‘He’s not phasing his body. He’s phasing the world around his body. He’s creating a localized field of 'non-interaction'.’
The Hunger purred. This was a delicacy. Izuku’s eyes were wide, the pupils dilated until the green of his irises was almost gone. He was no longer a boy in a crowd. He was a void, consuming the data of Phase-Shift’s every movement. He noted the sweat on the hero’s brow, the metabolic cost of maintaining the field. He noted the slight delay in re-solidification, the ‘cooldown’ of the atomic realignment.
But even this began to fade. The analysis was becoming complete. The mystery was being solved, and as the mystery died, the hunger returned, sharper and more demanding than before. He had finished the meal, and he was still starving.
He needed to see it closer. He needed to know what it felt like.
He slipped past the police line. He was small, unassuming, and "normal". The officers didn't even blink as he darted behind a pile of rubble. He was only twenty feet away from the hero now.
The battle ended quickly. The villain was restrained, and Phase-Shift stood catching his breath. The hero was alone for a moment, tucked in the shadow of a half-finished wall.
Izuku stepped out from the shadows.
"Your oscillation frequency," Izuku said, his voice flat and devoid of its usual stutter. "It’s not constant, is it? It’s a 12-hertz pulse. That’s how you manage the oxygen exchange. You solid-state your lungs for a millisecond between pulses."
Phase-Shift spun around, his hand instinctively going to his belt. He saw a teenage boy with messy hair and a notebook. "Kid? What are you doing here? This area isn't safe."
Izuku didn't move. He didn't look afraid. He looked famished. "But if you pulse at 12-hertz, there’s a vulnerability in the transition phase. If someone timed a strike at the 0.08-second mark of your cycle, you wouldn't be able to phase in time. Your quirk isn't a shield; it's a rhythm."
The hero narrowed his eyes. "Who are you? Are you a sidekick intern?"
"I'm just a student," Izuku said, taking a step closer. The air around him seemed to grow cold. The sinister nature of his gluttony was leaking out, a dark pressure that made the hero's instincts scream danger. "But I need to know. When you're phased... do you still feel the wind? Or does the air pass through your nerves without triggering a response? Is it lonely, being the only thing in the world that doesn't touch anything else?"
Phase-Shift stepped back. He had faced villains with knives, villains with fire, villains with the power to level buildings. But he had never seen eyes like the ones staring at him now. They weren't the eyes of a fan or a criminal. They were the eyes of someone who wanted to unmake him just to see how the pieces fit back together.
"Stay back, kid," the hero warned, his voice tight.
Izuku didn't stop. The gluttony was in control now. He reached out a hand, not to attack, but to touch the hero’s uniform, to feel the residual vibration of the quirk. "Please," Izuku whispered, and for a second, he sounded truly dangerous. "I just want to know. I will do whatever it takes to satisfy this."
Before the hero could react, Izuku’s mind made the final connection. He saw the way the hero’s atoms were settling back into a state of rest. He saw the microscopic tremor in the hero's hand. He saw everything.
The Hunger was suddenly, violently sated.
The rush of information was overwhelming. It was a flood of data points, a symphony of biological and physical laws being written in his mind in real-time. Izuku gasped, his knees buckling. He slumped against the construction debris, his breath coming in ragged hitches.
The dangerous aura vanished instantly.
He looked up at Phase-Shift, his eyes returning to their normal, bright green. He blinked, a look of utter confusion and embarrassment crossing his face.
"Oh... oh my god," Izuku stammered, his usual stutter returning with a vengeance. "I-I am so sorry! I... I get really carried away with my hero notes! I'm a huge fan, and I just... I started thinking about the physics and I didn't realize I was being so creepy! Please don't report me!"
Phase-Shift stood frozen, his heart still racing. He looked at the boy, this trembling, awkward teenager who looked like he’d be scared of his own shadow. The "predator" he had seen a second ago was gone. Had he imagined it? The adrenaline of the fight must have played tricks on him.
"Just... get home, kid," Phase-Shift said, though he didn't lower his guard until Izuku had scurried away into the night.
Izuku ran until he reached his apartment. He let himself in, his movements quiet so as not to wake his mother. He sat at his desk and opened his notebook. He wrote for three hours, filling forty pages with the most detailed analysis of "Phase-Shift" that had ever existed. He documented the 12-hertz pulse, the oxygen exchange vulnerability, and the metabolic exhaustion rate.
As he finished the last line, a sense of profound peace washed over him. The Hunger was quiet. The gnawing at his soul had stopped. He felt light, almost buoyant.
He was a normal member of society once more.
He looked at his reflection in the window. He looked like any other boy his age. But he knew the peace was temporary. He knew that in a few days, the void would open again. The gluttony for knowledge would return, and he would find himself back on the streets, hunting for another meal.
He smiled at his reflection, a small, polite smile.
"I wonder," he whispered to the empty room, "how All Might’s muscle mass stays consistent despite his injuries. Is it a reinforcement quirk layered over a strength quirk? Or is it something... more?"
The hunger stirred, a tiny, dark spark in the back of his mind. Izuku closed his notebook and went to sleep, dreaming of the day he would finally get to deconstruct the "Symbol of Peace." After all, he would do whatever it took.