After the events of the Poltergeisting, Misaka, Kokoro, Saten, and Uriharu find themselves born in the world of Remnant. With no knowledge on what happened, ot how to get back, they take up the mantle of huntresses as their best bet.
After getting rid of the spell put on Index, Touma found himself in a forest, covered in red leaves. With no knowledge of where he is, let alone any of his life beyond about a week-ish prior, who can he trust, and who must he fight.
(I'm putting the Poltergeisting Arc and the Index Arc at roughly the same time. Any canonocity problems I come across will be modified so that this works)
Arc 1 R: Entrance
Arc 1 I: Mysteries
"You're different from what I expected," she said softly.
"How so?" he asked, glancing at her.
"I don't know," she replied, searching for the right words. "You just... have this way of making people feel like they matter. Even here, in this... nightmare."
He was quiet for a moment before responding. "You matter, Y/n. Don't forget that."
OR
Y/n wakes up in the deadly Squid Game, surrounded by strangers and fighting to survive. What she doesn't know is that the mysterious Frontman is watching her every move through the cameras- and she's caught his attention.