Oh my gods. (My hero academia/Heroes of Olympus crossover)

Wait, what?

Being a demigod, you had to get use to a lot of things, especially quests given to you by lazy gods. Now, most of the time, you had a warning before you embarked on a quest. People would give you supplies, wish you good luck, tell you not to die, stuff like that. It’s not everyday you wake up in a different universe with no camp in sight and no clue how you got there.
Welcome to my world.
Now, Nico didn’t realize he was on a quest at the beginning. Honestly, his brain was going through a chant of ‘I'm being kidnapped, what happened, what in Hades did I do, this isn’t Camp Half-Blood, oh my gods.’
Once his brain stopped panicking and started to function normally he noticed, hey, I’m on a lawn. He was wearing his normal clothes (his aviator jacket, black skull shirt, and black jeans) and his sword was fastened on his side like always, even though the last thing he remembered was falling asleep in his skull print pajamas that Will got him as a gag gift awhile back.
In his left pocket, he thought he could feel a couple of golden drachmas and in his right coat pocket he pulled out a baggie of ambrosia squares. This was getting better and better.
He continued studying his clothes and trying to decide whether it was a weird dream, he was actually kidnapped, or he was magically transported on a quest.
He was done with the gods, honestly, pick on any other demi-god.
He looked up to realize he was on the lawn of a giant ‘H' shaped building and the whole property was surrounded by a metal wall. Of course, that’s when he noticed the cameras following his movements. Was he getting rusty or something? He hadn’t gone on quests or training because of his injuries from their last quest. Well, he thought his injuries WERE healed, but the Apollo cabin wasn’t having any of it.
He slowly stood up and held his hands in the air, then a blaring alarm came on.
“Great,” Nico mumbled.
Metal sheets slid over the windows, and since the whole building was made of glass, it was soon completely covered by protective metal. It didn’t really matter since, if needed, Nico could always just shadow travel inside, but whatever.
Nico didn’t have to wait long for people to show up, and he lowered his hands, keeping one hovering over his sword. He wouldn’t attack first since he was, you know, completely clueless to everything right now. Also, he had no clue if the people in front of him were enemies or not. But, he was prepared if they had to fight.
A couple of adults ran out the door, (that was quickly covered by that protective metal as well), immediately forming a semi circle around Nico. He’d been in enough fights to notice the others in a defensive stance and he shifted his weight, ready to spring into action if needed. His legs ached with protest and his back stung. Huh, maybe he wasn’t in the best health.
A man stepped forward, one hand on some sort of scarf around his neck and the other to the side, gesturing to the others to stand down. He had dark circles under his eyes that could rival Nico's and he was clad in a black long sleeved shirt and pants. Long black hair fell a little past his shoulders and his eyes were narrowed in suspicion. If Nico didn’t know better, he would have said something about them being related.
“Who are you?” the man asked. “Why are you here?”
Nico raised his eyebrows. Instead of answering, he shot the question back. “Who are you guys? Why am I here? Where is this place?”
A woman stepped forward and shot Nico a look. The lady’s hair was weirdly spiky and a black/purplish color. She seemed to be wearing a…costume? Her choice in clothing was, um, pretty unprotected. Now that he looked around, he realized none of them had any armor or weapons? Oh, wait, nevermind. The weird lady had a whip. But besides that, they had no knifes, spears, or visible weapons…yet they weren’t normal mortals. He could sense that.
“Who are we? You don’t know us? Or where you are? For goodness sake, you were the one who came here! You aren’t authorized and you teleported here, which, technically, gives us reason to attack or press charges. Explain yourself.”
Nico really couldn’t. He had no clue where he was, why he was there, or even how he got there. So, he played the part of a normal teenager and shrugged.
“Well, yeah, I don’t know you. Any of you, actually. And I don’t know this building, or where this building is.” Nico narrowed his eyes and the grass around started to wilt and die, the decay slowly spreading around him. He didn't exactly like being threatened. “I don’t suggest attacking me when I was the one who got summoned here. I didn’t teleport. Now, answer my questions.”
As soon as the grass started to die, the man in the middle stood forward. His eyes started glowing red and his hair flew up. Besides that, nothing happened. The man's eyes widened and he looked at the slowly decaying grass with interest.
“I can’t erase his quirk,” he said slowly. “It’s not a mutation type quirk, mine should be working.”
Nico stood silent as another adult spoke up. He seemed to have some sort of mask on, classic Texan boots, and a poncho with jeans.
“The kid could be under a memory loss quirk. If the decay quirk is his, someone could have transported him here with their quirk? And Eraser, your quirk doesn’t work on all types. His could be an exception.”
The lady kept her eyes on Nico and looked at him with distrust. He didn't mind that much, that was the usual reaction. She put a hand on her hip and countered. “You might be right, but he could also be a villain. Remember Himiko Toga? She’s the same age as our students! Two years isn’t a big age difference. Besides, he’s also using his quirk, which means this is counting as attacking us with unauthorized usage.” She pointed to the decaying ground.
Someone off to the side, which seemed to look like a human with a spinal problem got merged with a machine, sighed. “Go ahead, Midnight. But if this is an innocent civilian, you’re taking the blame.”
Before Nico could summon skeletons or fight back with his sword, purple smoke filled the air and he staggered to the side, head swimming. The smoke didn’t sting his eyes, or stop his breathing, but instead made him sleepy. That wasn't good.
He forced himself to stay upright and summoned three skeletons, equipped with armor and weapons, to attack the others. His strength was weakening. If he was going down by weird purple smoke, then go down injuring the people attacking you with weird purple smoke. Hah, try using that trick on skeletons with no noses.
His thoughts started slurring together. He heard alarmed shouts, then the familiar background noises of fighting. He thought he heard the woman saying, “He should have been down already,” but before he could be for sure, the ground came rushing towards his face and he blacked out.

(The crack crossover nobody asked for.)