Izuku in the Owl House!

A Game of Chess Perhaps?

Izuku held Amity close as the two of them fell.

She was no different, clinging to his cat hoodie as closely as she could.

It felt like they were falling for minutes.

Izuku couldn't open his eyes in fear of the darkness. He tried a light glyph but it just burnt up when he did.

Suddenly both Izuku and Amity hit ground.

Instead of being squished like a pancake, Izuku was surprised when the landing was soft enough to make him only tumble slightly as he held Amity.

"Are you okay?" Izuku asked opening his eyes to look at Amity. "Are you alright? Hey?!"

"M-M fine." She mumbled. "W-What happened?"

Izuku flinched and looked around.

The two of them were in a large cement room that had a table and a set of chairs.

"Hey..." Izuku said. "You wouldn't happen to know any... destructive spells would you?"

"I'd refrain from that if I were you." A squeaky voice said from an intercom.

Izuku grabbed his knife and stood in front of Amity, arm extended behind him to keep her close.

"Ah it seems you still keep your heroic and protective nature." The same voice said.

"Talk to me face to face or let us go!" Izuku yelled at the system.

"It seems you've also gotten a confidence boost." 

The flat cement walls retreated in one area revealing a steel door.

It opened and in walked a mouse that Izuku instantly recognized.

"N-Nezu?!" He said. "No... No No No..." He looked around for any other exit. "Why are we here?!"

"Well..." Nezu said sitting at the table with two chairs. "I honestly expected Kurogiri to only get you. Now... Who are you miss?"

"I'm-" Amity said before Izuku covered her mouth.

"Don't say anything." He said to her. "Don't talk don't answer don't react. Control your breathing Nezu is the smartest person alive in my dimension. Don't let his look fool you... if he had enough time he could take on both Eda, and the... number one system. All by himself."

Nezu snapped his fingers and a chair made of cement was created.

"Sit..." He said gesturing to the two chairs. "Please I insist."

Slowly, ever so slowly, Izuku and Amity sat down in front of him.

"Ah." Nezu said as if he had just uncovered a great mystery. "Mm... You can put the knife down Mr. Mid-"

"Don't call me that." Izuku growled out as he clenched the knife harder.

"Ahem..." Nezu said. "Izuku. Please put down the knife before we need to restrain you."

"You can't." Izuku said. "Restraining a shocked and confused victim is usually a one way ticket to getting your hero license revoked. You hear me Cementos?!"

"You are quite clever." Nezu said. "Nearly half a year away from your world and yet you still know our laws... Well most of them. You see that would only imply that you are a victim. But you're not a victim are you? You're a runaway who stumbled across some sort of dimensional portal and decided that instead of going to camp and not being a hero, you would become a runaway endangering the entirety of Japan by gong through a dimensional portal that destabilized our entire electrical system the second you walked through. Every time."