Alarms blared and lights flashed red and white, alerting everyone in Building U.S.J that there was an intruder. The students from class 1A looked around in confusion.

"What the hell?" Bakugo growled as he looked around for the teacher.

"What's going on?!" Rikuto shouted above the sirens. [Name: Terra Rikuto. Quirk: Ground Manipulation]

"Everyone remain calm!" Iida instructed, moving his arms up and down by his elbow joints like a robot.

Mr. Aizawa's voice came over a speaker system, drawing his student's attention. The alarms were silenced as he spoke. For once his board tone had an edge of caution in it. "Everyone return to the gate. An intruder has broken into this building and set off the alarms. They haven't been identified and could be a villain. Regroup at the gate, and try to avoid fighting if possible."

"An intruder huh?" Kirishima asked, putting his hands behind his spiky red hair. "Think it's a villain?"

"It could be someone from the media again," Todoroki added as they began making their way across the mountain terrain they had been practicing on.

"Its possible, but Mr. Aizawa's voice sounded a bit more cautious than usual," Deku said as he followed along. He put his hand under his chin and began to mutter, thinking to himself. "Its always hard to tell based on his monotone voice and general way that he speaks, but he seemed a bit more serious this time. It could be that he expects this to be a villain, so we should be cautious. It's not the first time villains have broken into this exact building to attack us..."

"Stop your muttering, damn nerd," Bakugo said in a surprisingly calm manner for him. He grinned and said, "If it is a villain I'll blast him to pieces." Looking back to the green haired boy he held his palm open and it sparked dangerously with mini explosions.

"Oh?" A voice none of them recognized questioned with a playful tone. "Is that what you'll do?"

They looked up to see a boy about their age standing high up on a tree branch, leaning almost carefree against the trunk. He had chin length orange hair that seemed to spike out in all directions, except the top was hidden beneath a black bowler hat. He was dressed in a black jacket with long coattails and an orange tie that matched his orange hair.

"Damn right," Bakugo growled. Using an explosion to launch himself up from the ground he lunged towards the newcomer.

"We are supposed to avoid fighting," Iida scolded, but the blond had already taken off.

"I expected better manners from a hero," the boy with orange hair said with a smirk. He lifted ok hand in front of him and spread his fingers wide.

"Kacchan!" Rikuto shouted in warning, stepping forward as to reach for him. There was a flash of light that drew everyone's attention. Terra blinked to shield her eyes, then slowly aware that the ground where she had been stepping to was gone and that she was falling.

A story of trap door had opened beneath her and she had fallen into it. The doors frame stretched too far away for her to grab onto, and she was too far through it to catch herself. She was too far gone for any of her classmates or their quirks to reach her. The door snapped closed behind her and the light faded away, erasing any trace that a door had ever been there.

"Oh crap! Rikuto!" Kaminari shouted, still going over to where the door had vanished.

All the commotion had distracted Bakugo, who turned his head back just in time to see the light disappearing where Terra had been, and some of their friends reaching towards the empty space. His eyes widened in surprise. Terra was gone? He forgot just for that moment that he was still flying through the air towards the villain, until another flash of light opened a door in front of him. It was too late for him to slow his momentum, and he flew through the second door.

"Bakugo!" Kirishima shouted in surprise.

"You know what?" The newcomer said, tilting his head as he thought. "This may be more fun-"

As he thought there was a flash of light brighter than the previous one. Through gasps of pain the remaining class was forced to shield their eyes with their hands, then were followed by shouts of surprise as the ground beneath them gave out and they fell through a giant door.

"-if everyone came along." The villain chuckled before disappearing into his own door.

==========

Rikuto was still falling. The door had opened up in the sky and she was plummeting towards the ground. She was majorly screwed. There was nothing she could do in the air. She looked up to see if the door was still visible and saw that her classmates were falling above her. The door behind them disappeared into nothing.

"We need a plan or most of us are dead!" Tokoyami shouted over the wind rushing past.

"Everyone join hands! Uraraka! Be ready to use your quirk!" Momo shouted directions. Everyone immediately began to do their best to reach one another, but it was taking time and the ground was getting closer.

Sero used his tape to connect Ojiro and Koda and drag them over to the main group. Most of them were close and would be able to grab onto each other. Tsu thought it was unlikely, but she would do her best to reach Bakugo with her tongue. He had fallen before them and was farther away, possibly out of reach. That also meant that Rikuto, who had fallen first, was way outside of the groups range.

"Terra!" Todoroki shouted, realizing that if they wanted their plan to work, they wouldn't reach her.

"Don't do it!" Rikuto yelled at them, knowing that it was very likely that they could die trying some risky plan that would only have a slim chance of saving her.

"Terra!" Deku shouted, realizing that she was telling them to just let her fall. Momo was already moving on and talking to Tsu about if they could reach Bakugo on their end. She didn't have enough time to make much with her quirk, but maybe if she made a small rope and gave it to Tsu...

"You guys do your thing! I'll get Terra!" Bakugo shouted. Before anyone could protest, he used his explosions to force himself to fall towards the ground faster, reaching for Rikuto.

"Kacchan!" she shouted, unsure if she was relieved that he was coming for her or pissed that he was trying something so reckless. She reached out and grabbed his hand so they could pull each other close.

"Hold onto me!" He instructed, guiding her so that she was be hind him, one of her hands wrapped around his shoulder and the other under his other arm, leaving his hands free. He aimed them towards the ground and began firing off explosions, trying to slow their momentum.

Rikuto's arms were pushing their limits as she clung to Bakugo, who was pushing the limits of his quirk, but it seemed to be working. Their falling speed was slowing, but would it be enough? Uraraka was using her Zero Gravity on and off, to make them all float and fall in small increments, but turning it on and off with so many people was draining. Midoriya looked down to the ground, trying to gauge if they could make it. Below them seemed to be a circular tower, with sharp spikes at the top. The spikes turned inward as they began falling towards it at an alarming rate. Were they falling faster? No, he realized, it was moving upwards. 

"Look out!" he shouted, realizing that Terra and Kacchan would hit first. Bakugo had already seen it, and tried to aim an explosion to the side, pushing them in another direction, but the building moved on its own. The circle grew wider and they realized that the brick building and spikes looked more like a mouth. It reached up and to the side, causing Bakugo and Rikuto to fall into it. Then it took a sharp turn back towards the others and engulfed them as well. 

The opening closed behind them, forming a brick ceiling. Below them was a fast approaching floor. They resorted to their previous falling techniques to try to slow themselves. Most of them collided with the ground at a slower pace, but hit hard enough to leave them on the ground with a few bumps and bruises. 

"Hey, are you okay?" Bakugo panted, as he laid on the ground next to Terra. 

"That was stupid and reckless," Terra scolded him. 

He just grinned back and replied, "It was the heroic thing to do."  She didn't have a retort to give him. At least they were alright. She looked over to the others who were picking themselves off the ground. 

"Whoa! What is this place?" Aishido asked, a bit of fear creeping into her usually cheerful voice. The room was circular, but stretched up multiple stories. The entirety of the walls were covered in doors, some of which had mouths that opened and closed with sharp teeth, and some had a giant eye in the center that moved around and watched them. In the middle of the room was a giant crystal ball floating above a pedestal. 

"Welcome! Welcome!" the villain said, his face appearing in the crystal ball. All of the students jumped to their feet and got ready for a fight. "Welcome to my domain! Now, I'll make this as brief as possible. All around you and constantly moving are special doors created with my quirk. These doors will lead you to alternate dimensions."

"Alternate dimensions? Like other worlds?" Hakagure asked. 

"Yes, but pay attention! I am not going to repeat myself and I'm only going to tell you these things once," the orange haired boy snapped impatiently. "So each of these doors leads to somewhere outside of your own dimension. Some parallel to our own, with only slight changes, some entirely different. Doors with eyes are places that have already been explored, doors with mouths are entirely new. Once you go through a door it is very likely to close. Once you complete a quest or the world is satisfied with you, a new door will appear and lead you back out." 

"It sounds like a game. Why would we want to waste our time playing Villain?" Tokoyami asked. 

"You can address me as Trickster," the villain growled, annoyed at being interrupted again. "And you'll want to go through the doors because I am standing behind one of them, and behind me is the door back to your world. Quick tip: I am standing behind the a door that hasn't been explored yet. I was going to give you a bit more information but because you're so rude and interrupting, I'm gonna end my introduction here." He huffed in anger, but then grinned as he looked at each of them. "Well fine, one more quick tip. Watch the doors. They have a mind of their own." 

He closed his eyes and his face disappeared from the orb, leaving it blank. Deku let out a gasp as he realized that he was falling. He looked down to see that a door had shifted to below him and swung open.  Beneath him was just a black white light. 

"Deku!" Terra shouted, grabbing her green haired friend's hand. As she did, the door opened its mouth just a bit wider to cause her to fall in too. Their classmates lunged for them, but the door swung closed and faded into the ground, disappearing entirely. 

"Damn it!" Bakugo swore in frustration. 

===== Author's Note =====

Hello friends! This is just a fun fic that I'll be working on between my other works, so updates will be slower, but maybe longer? 

In a way it branches off my MHA fic 'To Be a Hero', but it won't affect that story at all. Terra Rikuto and Trickster are mine, and so far all the rest do not belong to me. 

Comment if you've got a world/dimension you'd like to see! 

Thanks for reading!