Chapter Text
The sky above the ruined city wasn't blue anymore; it was a fractured canvas of swirling violet and blinding green, torn apart by the absolute limit of One For All’s accumulated energy collapsing inward. Adult Izuku stood at the center of the temporal storm, his boots sinking into the cracked asphalt.
His armor was shattered, the breath rattling heavily in his chest as the sheer gravitational pull of the anomaly began to compress the space around him. The vestiges were a deafening chorus in his mind, their voices overlapping as the quirk’s core prepared to force its bearer backward through the stream of time.
Shizuka stood right at the edge of the distortion, her indigo hair whipping wildly in the gale-force winds. She wasn't a hero, but her calm, intelligent eyes held no fear—only the fierce determination of a mother who knew exactly what was at stake.
"The anchor is slipping!" Izuku shouted over the roaring thunder of the timeline fracturing. The green lightning of One For All began to reverse its flow, wrapping around his forearms like tightening chains, physically pulling him down, shrinking his proportions piece by piece.
"Shizuka—!"She stepped forward into the pressure wave, her hand cutting through the static to lock firmly onto his armored gauntlet. Her grip was steady, the one grounding force left in a world that was actively erasing itself. "Don't look back, Izuku," Shizuka said, her voice dropping into that quiet, unshakable timber that always cut through his panic. "The future is already gone. But he is out there in the past. Find him. Before the world falls apart, find our boy." The light swallowed them entirely.
The physical sensation of his adult body—the hard-won muscle, the deep scars, the years of combat conditioning—was violently compressed, folded away by the raw power of the paradox.
His consciousness plunged into a freezing, dark void as the timeline snapped shut behind him, hurtling his mind back toward a time before the war ever began.
The roar of the collapsing universe vanished, replaced by a deafening, sudden silence. A sharp gasp tore from his lungs as his eyes snapped open. There was no smoke, no shattered asphalt, and no scent of ozone. Instead, the smell of laundry detergent and old paper flooded his senses. Izuku sat up fast, his heart hammering against his ribs like a trapped bird.
He looked down at his hands—they were small, unscarred, and completely devoid of the heavy calluses earned from years of frontline warfare. He was back. But as he tried to grasp at the memory of why his chest ached with such profound grief, or whose steady hand had just been holding his gauntlet, the thoughts slipped through his fingers like sand. A heavy, dark curtain fell over his adult consciousness, locking the future away behind a wall of temporal trauma. He didn't remember the war.
He didn't remember Shizuka.
He didn't even remember that he was a father. Yet, as he looked out the window at the peaceful, sunlit streets of Musutafu, his eleven-year-old body hummed with an unnatural, restless instinct. The mind was asleep, but the muscles remembered how to fight.
For the next two years, Izuku lived a double life he didn’t even understand. By day, he was the quiet, unassuming eleven-year-old kid who sat in the back of the classroom, flinching at Bakugo's explosions and muttering endlessly into his notebooks.
He seemed entirely ordinary, completely quirkless, and utterly defenseless. But by night, the phantom muscle memory took over. The moment the sun dipped below the horizon, an unnatural restlessness would drag him out of his bedroom window.
He didn't have One For All's lightning yet, but his body possessed the flawless kinetic pacing, the precise weight distribution, and the ruthless close-quarters combat forms of a seasoned frontline soldier. He began patrolling the lower districts of Musutafu under a heavy, oversized cloak. He didn't speak. He simply intercepted threats with terrifying, silent precision. Because his tactical awareness was so highly developed, the local gangs and the underground hero networks whispered rumors about a brilliant, dangerous new adult operator pulling strings in the shadows. No one suspected the truth. Even Izuku himself didn't understand why he was doing it—he just knew, deep in his chest, that he was looking for someone. A ghost he couldn't name.
Then, on his thirteenth birthday, the mental dam finally broke. It happened during a routine night patrol. A specific sound a streetlamp caught a flash of indigo hair in a distant alleyway—slammed into his subconscious like a physical blow. The heavy curtain over his mind shattered. The locked memories of a dark future, the terrifying battles, the quiet strength of Shizuka, and the undeniable truth of his paternal bloodline flooded his thirteen-year-old brain all at once. Izuku stumbled back against a brick wall, clutching his head as a sharp gasp tore from his throat. His emerald eyes snapped open, no longer wide with childish innocence, but ancient, calculating, and suddenly sharp with absolute clarity. Hitoshi.
The pressure in his skull gradually receded, leaving behind a cold, crystalline focus. Izuku let his hands drop from his face, staring down at his small, thirteen-year-old palms. Two years of phantom patrols suddenly made terrifyingly perfect sense. The muscle memory hadn't been a glitch; it was his future self screaming to keep the edge sharp. He didn't waste time mourning the world he had left behind—Shizuka had told him exactly what to do. Find our boy.
But logic quickly reasserted itself. Hitoshi would only be around twelve years old right now, likely struggling with the heavy societal stigma of a "villainous" mind-control Quirk, completely unaware of his true lineage or the genetic echo sleeping inside his DNA. If Izuku just marched up to him as a fellow middle-schooler and claimed paternal rights, the temporal paradox alone would fracture their lives before they even started. He needed to remain a shadow. He needed to become the protector Shizuka asked for, but from the safety of the mask.
Pulling the heavy, oversized collar of his cloak higher around his face, Izuku slipped away from the brick wall and melted back into the dark alleys of Musutafu. He had a lineage to track, an underground reputation to solidify, and a son to find.
Finding a specific twelve-year-old in a city as sprawling as Musutafu would have been impossible for a normal middle schooler. For a seasoned tactical analyst with two years of established underground informants, it took less than a week. Izuku crouched on the rusted iron ledge of a fire escape, the dark fabric of his oversized cloak billowing slightly in the cold night air. His sharp emerald eyes scanned the dimly lit alleyway below.
Down there, a young Hitoshi Shinso—looking small, exhausted, and carrying those familiar, heavy under-eye shadows—was backed against a chain-link fence. He had let his anger get the better of him, trying to stop a couple of low-level street thugs on his way home from school. He was entirely outmatched. One of the thugs lunged forward, a minor kinetic quirk sparking across his knuckles. Before the blow could land, a blur of dark green and black dropped from the sky. Izuku intercepted the attacker mid-air, landing with flawless kinetic precision. Using the momentum, he executed a precise, non-lethal submission sweep, sending the first thug crashing into the concrete.
The second didn't even have time to react before Izuku caught his wrist, twisted his center of gravity, and hurled him back out toward the main street. The alley fell dead silent, save for the heavy panting of a startled twelve-year-old.Hitoshi scrambled to his feet, his jaw clenched, defense mechanisms instantly kicking in. Frustrated and overwhelmed, he didn't run; instead, he lunged at his masked savior, throwing a wild, undisciplined punch. Izuku didn't flinch. He easily deflected the strike, stepped into Hitoshi's blind spot, and firmly pinned the boy's arms behind his back, completely subduing him without inflicting a single bruise. "Let me go!" Hitoshi hissed, struggling against the iron-tight grip. Izuku slowly released him, stepping back into the shadows of the brick wall to obscure his smaller frame, altering his vocal pitch to sound like a detached, seasoned operative. "You have incredible spatial awareness and great potential," Izuku said, his voice cutting through the damp air. "But your form is reckless. What is it you want to do with those hands?" Hitoshi rubbed his wrists, glaring through the darkness at the hooded figure.
"I'm going to be a hero. I don't care what anyone says about my quirk." He paused, his sharp eyes trying to pierce the shadow of the cloak. "Why are you out here? Why are you a vigilante?"
Izuku stood perfectly still. The weight of a hundred unwritten conversations pressed down on his chest, but he kept his voice steady, delivering the foundational promise that would guide them both. "Your father... a man who passed away before you were ever born... looked at me before he left this world. He asked me to protect you when the path got too heavy. That was your father's dying wish." Izuku pulled his hood lower. "And so, I will help you train. I will help you survive to get into UA, even if it is the last thing I do."
For the next three years, Izuku wore two entirely different faces. By day, he was the quirkless, unassuming student navigating the final years of middle school, eventually meeting All Might and receiving the immense, burning torch of One For All. By night, he was the ghost in the heavy cloak—the relentless mentor who dragged Hitoshi Shinso through hell to ensure he could survive the heaven of UA. They trained in the forgotten, rusted corners of the Dagobah Municipal Beach park before Izuku cleaned it up, and later in abandoned warehouses where no heroes patrolled. Izuku didn't just teach Hitoshi how to punch; he taught him structural anatomy, situational awareness, and how to read the slight shifting of an opponent's weight a second before an attack landed.
He forced Hitoshi to train with a weighted capture weapon until the boy's forearms bled, building the exact muscle memory needed to compensate for a non-physical Quirk. "Again," Izuku would command, his voice masked and distorted, throwing another strike that Hitoshi barely dodged. "The world won't wait for your voice, Hitoshi. If they know your Quirk, they will close their mouths and use their fists. You have to be faster."
Hitoshi never complained. Driven by the memory of a father he never knew and the absolute, unyielding discipline of the only person who believed in his dream, he pushed past every physical limit. He grew taller, his movements sharper, his gaze narrowing into the cold, calculated precision of an underground fighter. He went to a different middle school, completely isolated from Izuku's daily life, keeping their bond entirely in the dark. By the time the cherry blossoms began to bloom three years later, the training ground changed. The morning of the UA Entrance Exam arrived, crisp and biting. Standing at the massive gates of UA High School, Hitoshi adjusted the collar of his tracksuit, his sharp indigo eyes scanning the crowd of nervous applicants. His chest hummed with a strange, deep warmth—a phantom spark hidden deep within his genetic makeup that always seemed to wake up when his adrenaline spiked. He didn't know what it was, but he knew he was ready. A few yards away, blending perfectly into the crowd of screaming teenagers, Izuku Midoriya adjusted his own yellow backpack. The power of One For All swirled steadily beneath his skin, fully realized and under control. He didn't look back at Hitoshi. He didn't give away a single hint of recognition.
But as Izuku looked up at the towering glass structures of the academy, a small, ancient smile touched his lips. Phase one is complete, Izuku thought, stepping forward into the gates alongside the son he had crossed time to protect. Let’s see what you can do.