Hey I have an idea for a crossover fic

Between demon slayer and mha

Start at when muzan turned tanjiro into

A demon and he break out of craze to late

Because he already killed everyone he loved.

Then he isolated himself by going inside

Of a cave for 500 years (since bnha set in

2400s. I Google that)(and kny is set in 1912)

And then a group of villain rediscovered the cave(since he destroyed the entrance when came in)

Or Alternatively

A group of archaeologist rediscovered the cave