Chapter 10: The Infiltrators

The moment they stepped inside USJ, the air felt different.

It was huge. Bigger than Izuku imagined. Fake skies arched overhead. Buildings stood in strange positions. Water shimmered in massive zones. Everything looked real enough to trick the eyes, but wrong enough to remind you it wasn’t.

“Whoa…” someone breathed.

“Is this really all for training?” another voice said.

Izuku stayed close to the back, hands folded in front of her, eyes moving slowly as she took it all in. Every detail. Every exit. Every shadow. Old habits never really left her.

Then a figure came down gently in front of them.

“Welcome, everyone.”

The voice was warm. Calm. Friendly.

Thirteen landed softly, boots touching the ground without a sound. Her space suit gleamed under the artificial lights, helmet reflecting the wide-eyed faces of Class 1-A.

“I am the Space Hero, Thirteen,” she said cheerfully. “And today, I’ll be guiding you through rescue operations.”

The reaction was instant.

“OHHHH MY GOD, ” Ochako practically launched herself forward.

“That’s her!” she shouted. “That’s Thirteen! The real one! The black hole hero!”

She bounced on her toes, hands flailing, eyes sparkling like she’d just met a celebrity from another planet. “I’ve watched every interview! Every documentary! Your quirk is amazing!”

Aizawa didn’t even look surprised.

He reached out and grabbed Ochako by the back of her collar like a cat.

“Ochako,” he said flatly.

She kept wiggling. “Sensei please just one second just one second I swear I won’t touch anything, ”

Her feet kicked the air as she stretched her arms out dramatically. “Thirteen-sensei! I’m your biggest fan!”

Thirteen froze.

Awkward silence.

Then she laughed nervously. “Ah… wow. That’s, um. Thank you?”

Ochako somehow leaned even farther forward. “Could I maybe get an autograph?”

Aizawa stared at the ceiling like he was reconsidering every life choice he’d ever made.

“…Fine,” he muttered. “Quickly.”

Thirteen blinked. “Oh. Uh. Sure?”

She wiggled closer and awkwardly signed Ochako’s notebook while Ochako vibrated with joy.

“This is the best day of my life,” Ochako whispered.

Izuku watched quietly. Her eyes softened just a little.

Thirteen cleared her throat once the autograph situation was resolved. “Alright! Let’s begin.”

She pulled out a tablet and tapped the screen. A holographic list appeared, displaying Class 1-A.

“Midoriya, Izuku,” Thirteen read aloud.

Izuku stiffened slightly.

“Quirk: Cursed Speech,” Thirteen continued.

A few students glanced her way. Izuku kept her gaze forward.

Thirteen smiled gently in her direction, not pushing. “I’ve prepared exercises suitable for everyone here.”

Murmurs spread.

“All of us?” Kaminari asked. “Even the really destructive ones?”

“Yes,” Thirteen said. “Especially the destructive ones.”

Bakugou scoffed. “Tch.”

Thirteen turned, serious now. “Before we start, I want you to understand something.”

She gestured around them. “Rescue operations are the backbone of hero work. Fighting villains looks flashy. It looks cool. But saving lives is what really matters.”

Sero raised his hand. “So, uh, what exactly does your quirk do? Like, in simple terms?”

Thirteen nodded. “My quirk is Black Hole. I can create a vacuum that absorbs matter.”

Some students gasped.

“I can disintegrate almost anything,” she continued. “That’s why I specialize in rescue. Precision matters. Control matters.”

Hagakure tilted her head. “But isn’t your quirk like… perfect for rescue? What about people whose quirks don’t fit?”

Thirteen smiled. “That’s a good question.”

She spread her arms. “There’s no such thing as a useless quirk in rescue work. Strength clears debris. Speed delivers aid. Sound can guide. Even quirks that seem dangerous can save lives if used correctly.”

Her visor turned slightly toward Izuku.

“Sometimes,” Thirteen added gently, “the most dangerous powers require the most responsibility.”

Izuku’s fingers curled slightly.

Thirteen clapped her hands. “For today, you will follow my instructions exactly. No improvising. No showing off.”

She looked directly at Bakugou.

“No exceptions.”

Bakugou clicked his tongue but said nothing.

Todoroki raised his hand. “Where is All Might?”

The room paused.

Bakugou crossed his arms. “Yeah. Where’s he at?”

Aizawa sighed. “He was supposed to be here.”

He looked around briefly, then shrugged. “He’s late. We’ll start without him.”

Thirteen nodded. “Alright then. Let’s begin.”

Izuku took a slow breath.

Something in her chest felt tight.

But she stayed where she was.

Quiet.

Ready.

Unaware that everything was about to change.

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The air changed first.

It was subtle. Almost polite. Like the room had taken a quiet breath it did not need.

Izuku felt it before she saw it.

Her shoulders stiffened. Fingers twitched. Her eyes lifted from the ground just as something strange crept across the floor.

Purple mist.

It rolled low at first, thin and lazy, like fog crawling out of nowhere. It curled around Thirteen’s boots. Slipped between students’ feet. Licked the edges of the training zone like it was curious.

Someone laughed nervously.

“Uh,” a short boy with purple balls stuck to his head squinted at it. “Is… is this part of the lesson?”

A couple of students chuckled. Weakly.

“Whoa,” another voice said. “That’s some next-level special effects.”

Mineta tilted his head. “This lesson’s kinda scary though, not gonna lie.”

Thirteen froze.

Her body went stiff. Her helmet turned sharply, scanning the mist. Her voice lost its cheer instantly.

“No,” she said. “This is not part of the program.”

The words hit heavier than any shout.

Aizawa moved immediately.

“Everyone, stay back,” he said, already stepping forward. His posture changed completely. Lazy slouch gone. Eyes sharp. Scarf loosening, ready.

The purple mist thickened.

It rose higher now. Swirling. Pulsing. And then, 

It opened.

Right in the air.

Like space itself had been unzipped.

A portal bloomed open, dark and swirling, edges glowing violet. Then another. And another. Dozens of them. All around USJ.

Figures stepped out.

Men and women dressed like street punks. Masks. Scarves. Torn clothes. Weapons in hand. Smiles sharp and ugly.

They poured out slowly at first. Then faster. Boots hit the ground. Laughter echoed. Knuckles cracked.

They looked hostile.

No hesitation. No confusion.

Real villains.

“This is not a drill,” Aizawa said calmly, but his voice cut through the chaos like a blade. “Iida. Take everyone and run out of USJ. Now.”

Iida snapped straight. “Y-Yes, sir!”

The students turned as one, 

And froze.

The exit was gone.

Purple mist swallowed it whole. A wall of swirling fog blocked the path where the doors had been seconds ago.

“What, ?” someone gasped.

Bakugou snarled. “Tch. Move.”

He stepped forward, palms already sparking. “I’ll blast through.”

“Bakugou, wait— ” Iida started.

Too late.

Bakugou lunged.

Explosion crackled.

And the mist swallowed him.

He vanished mid-step.

“What?!” Kaminari shouted.

More portals opened.

The mist surged like it was alive.

It rushed forward, engulfing students one by one.

Hands reached out.

“Wait!”

“Sensei!”

“I can’t see!”

Izuku felt it wrap around her ankles.

Cold.

Heavy.

Her breath caught.

Her instinct screamed.

She reached for her collar but, 

The world twisted.

Her stomach dropped like she had been thrown off a building.

The ground vanished.

Wind roared in her ears.

And then, 

She slammed into something hard.

A rooftop.

She slid.

Fast.

Toward the edge.

Strong arms grabbed her from behind.

“Whoa, !”

Sero wrapped his tape around a railing and yanked back, skidding on his heels as he pulled Izuku away from the drop.

They crashed into the concrete together.

Izuku gasped, chest heaving.

“S-salmon,” she breathed.

Sero blinked, then grinned nervously. “Ah. Uh. You’re welcome.”

He let go carefully. “Guess that means thanks, right?”

Todoroki stood at the edge of the building, one foot forward, eyes scanning the chaos below.

Villains everywhere.

Students scattered across different zones. Water splashing. Fire erupting. Screams echoing.

“This is a coordinated attack,” he said quietly. “Inside UA facilities.”

He clenched his fist.

“In UA.”

Izuku pushed herself up, heart pounding.

Her hands shook.

But she stood.

Ready.

Even as the world burned around them.

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The purple mist shifted again.

From the largest portal, something stepped out that did not rush, did not stumble, and did not hesitate.

He was huge.

Muscles packed tight under blue skin. His posture was straight. Too straight. Like a statue that had decided to move on its own. His head was shaped like a bird’s, sharp beak, hollow eyes that did not blink. Feathers or something like them ran along his arms and shoulders. He stood there without breathing hard, without reacting to the chaos around him.

Still.

Then another figure followed.

This one moved wrong.

He stumbled out of the portal like he hated the ground beneath his feet. Blue hair fell messily over his face. His skin was pale, almost sickly. Hands were attached to his body in places they should not be. One on his face. One on his neck. One gripping his arm. Fingers dug into skin like they were holding him together.

He scratched at his neck, nails dragging over irritated flesh.

“So this is UA,” he muttered, voice dry, almost bored.

His eyes wandered lazily until they landed on Aizawa.

“A pro hero?” he said, tilting his head. “Huh.”

He scratched again. Harder.

“Now,” he added, looking around the facility, “where’s All Might?”

The villains around him snickered.

Aizawa did not flinch.

“How did you know All Might would be here today?” he asked calmly.

The blue haired man froze.

Then his face twisted.

“What?” he snapped.

His voice rose fast. Sharp. Ugly.

“Why isn’t All Might here?” he shouted, claws digging into his own neck. “Huh?”

He took a step forward, rage spilling out of him in waves.

“I came here to kill him,” he yelled. “Shigaraki Tomura is here to kill All Might.”

The bird-like man beside him did not move.

Shigaraki turned sharply to the crowd of villains.

“Oi,” he snapped. “What are you idiots waiting for?”

He flung his arm out, pointing.

“Beat those two heroes,” he ordered. “Break a few bones. All Might will come running once you hurt them enough.”

The villains roared.

They surged forward.

Aizawa and Thirteen moved at the same time.

Thirteen floated back slightly, hands raised, positioning herself near the rescue zones. Her voice stayed steady even as danger closed in.

Aizawa stepped forward.

His scarf snapped out like a living thing.

“Mina. Iida,” he said sharply without looking back. “Try to get out of the facility and alert everyone.”

Iida hesitated. “But Sensei, ”

“Now,” Aizawa said.

Then he moved.

The scarf whipped through the air, wrapping around the first attacker’s arm and slamming him into the ground. A second villain rushed in. Aizawa ducked, kicked, and spun, taking them down with clean, precise movements.

The bird-like man and Shigaraki stood side by side.

Shigaraki tapped his fingers impatiently against his arm.

“Nomu,” he muttered. “Stand by.”

The bird-like man did not respond.

He did not blink.

He simply waited.

Aizawa crashed into another group of attackers, scarf snapping, eyes sharp, body moving without wasted motion as the real battle finally began.

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