Archive of Our Own ^beta

Chapter Text

The streets of New York were burning.

Again.

But this time—this time—it wasn’t just another nightly scrap. The Krang were pulling out everything.
No more subtlety. No more infiltration. No more harvesting.

This was a war.

Michelangelo ducked behind a crumbling yellow cab, breath ragged, nunchaku shaking in his hands. Plasma bolts hissed overhead, melting street signs and exploding the pavement. Across the battlefield, Donnie was calling out coordinates, barking instructions into his comm. Raph had long since stopped listening, charging into the fight with blood in his eyes. Leo was everywhere and nowhere, guiding, guarding, bleeding. And Mikey? He fought.

He fought like it could be his last breath. Because it might be.

His body was bruised, armor scraped and scorched, but his heart—his heart still beat. Fast. Furious. Terrified. But it wasn’t fear for himself.
It was for his family.

And for him.

“Leatherhead, duck!” Mikey screamed, voice hoarse as the gator-man crushed a Krang droid into the pavement with a roar. They were side by side, back to back. Like always. Like brothers. Like—

That’s when it happened. The air rippled.

A sound like reality screaming tore through the air.

The portal opened.

Toxic pink, violent, spitting thick pink gas that burned the lungs and made the eyes water. A shape loomed from within, towering, glinting under the burning streetlamps.

A mech.

Not Krang-like, not really—not the usual jelly-in-a-suit model. This was something else. Taller than a tank, crab-legged, loaded with cannons. It screamed as it dropped into the street. And then—

Laser fire.
Blinding.
Explosive.
Searing.

The ground shook.

Mikey couldn’t breathe.

He was yelling something. Anything. But he didn’t hear his own voice. Just ringing. Smoke. Pain.

And then—
"Mikey!"

He turned, just in time to see it.

A blast, center mass.

Leatherhead.

Time slowed. His body arched. Slammed into the wall. Concrete cracked. His tail twitched. His fingers curled once.

And then nothing. The silence in Mikey’s head wasn’t silence. It was the eye of a hurricane. A pressure. A scream waiting to be born. He didn’t remember moving. Didn’t remember standing. Didn’t remember the sound that tore from his throat. But his brothers heard it.

It wasn’t a scream.
It was a roar.

And when they turned—when they saw what had become of Mikey—they didn’t see their baby brother.

They saw a monster.

Orange mask stained black with ash. Eyes glowing—not metaphorically, literally—a reflection of the fire burning around them. His stance shifted, lower, predatory. Nunchucks spinning too fast to follow. His laugh was gone. His soul screamed through every swing. Donnie flinched. Raph stopped mid-punch, gaze wide. Leo froze, twin blades limp in his hands.

Because Mikey wasn’t just fighting anymore.

He was destroying.

The mech turned to fire again—and Mikey was already there. Climbing it. Punching into its joints. Shoving a Krang blaster into its cannon socket and firing. The explosion lit the sky.

Pieces of Krang metal rained down.

Mikey stood in the middle of it. Alone. Panting. Shoulders shaking.

His hands dripped purple.

His brothers approached slowly, like walking up on a wounded animal.

“Mikey…” Leo tried.

No response.

“Mikey, bro,” Raph said, softer than he’s ever spoken.

Still nothing.

Only when Donnie placed a trembling hand on his shoulder did Mikey flinch. He blinked. Once. Twice. The rage fog peeled away—
—And what was underneath it?

Grief.
Crushing.
Endless.

He dropped to his knees.

“I couldn’t save him,” he whispered. His voice sounded like it came from someone else.

His hands trembled. “He—he saw me. And I—I didn’t even see it coming. I didn’t stop it. I didn’t—”
He choked.

Leo wrapped his arms around him first. Donnie joined. Then Raph.

They held him through the fire.

But they never forgot the thing that had come out of him.

The thing that made the Krang run.

The thing that took over when Mikey was gone.

A monster.

One that lived in the heart of the brightest brother.

And they knew—if he ever lost someone again—

It would come back.

Chapter Text

The city didn’t sleep anymore.
Not because of the Krang.
Not because of the Foot.
But because of him.

Michelangelo. They still called him Mikey, but the word didn’t fit. Not anymore. Since Leatherhead… since that night… something inside him had cracked and bled out into the world. The boy who once joked through battles, who spun his nunchaku like a circus act, who laughed even when he was scared,he was gone. What stood in his place was something sharper. Something darker. Something hungry.

The first time it happened, they thought it was grief. A squad of Foot had cornered them in the alleys near 5th Avenue. Routine. Easy. They’d fought the Foot a hundred times before. But this time… Mikey didn’t stop. Raph had already knocked his guy out. Donnie had disarmed three more. Leo had told them to retreat. But Mikey… Mikey kept swinging. Nunchaku to the jaw. To the ribs. To the skull. The crack of bone echoed like gunfire. The ninja was down, screaming, twitching, and still Mikey struck, until Raph ripped him back, arms locked around his chest.

“Mikey, enough!”

Mikey’s voice was low, feral. “They don’t stop. So why should I?”

His mask was soaked in blood, and for the first time, Leo saw something in his brother’s eyes that didn’t belong there. It only got worse. The Krang fared no better. Where Raph smashed and Donnie calculated and Leo cut with precision, Mikey annihilated. Krang bodies didn’t look like bodies when he was done with them. Just puddles. Mush. Guts steaming in the gutter. And the look on his face—calm, detached—wasn’t Mikey at all.

“Bro, we need to talk,” Raph said one night, blocking the doorway to the lair when Mikey returned from patrol. His nunchaku still dripped purple.

“Move.”

“Not until you hear me.”

Mikey’s head tilted, eyes burning like twin suns under the orange cloth. “You think you can stop me?”

The air in the lair went thin. Donnie put down his tools. Leo’s hand hovered near his swords. For a second, just a second, Raph saw something else. Not his brother. Not even a turtle. But something wearing his skin. A shadow with teeth. Mikey stepped closer, chest brushing Raph’s. His voice dropped to a whisper.

“They took him from me. And if the world wants to keep taking, then I’ll burn it down before I let them win.”

That night, Donnie heard him muttering in his sleep. Violent things. Bloody things. Words he didn’t even know Mikey knew. And sometimes, when he woke up screaming, it wasn’t Leatherhead’s name on his lips. It was theirs.

Leo prayed he could pull his brother back. Raph swore he wouldn’t let him slip. Donnie searched for answers in his tech, his formulas, his endless calculations. But deep down, all three knew the truth. Mikey wasn’t fighting grief anymore. He was feeding something else.

And whatever it was—
It was in control.