Yeah. That's what I'm hoping too, that he becomes the demon king. Especially when i saw the misfits having a feast as adults back then (i forgot the chapter) but it could also be like the mha ending. Where in the end, izuku ended up being a teacher (still no.4 hero by the way) and not the no.1 hero. Instead, it was Lemillion who got no.1. I can see it happening tbh. Iruma becoming a teacher while Sabnock becomes the demon king. But either way, I hope the manga continues and this is not the end. ( T﹏T )
I don't really keep up with MHA but the ending was a bit unfortunate but it kind of makes sense for it to happen??? but the thought of Iruma as the king makes more sense due to the prophecy back in season one from Sabnock's memory but yeah, Iruma becoming a teacher might happen but I lowkey hope it doesn't ┗( T﹏T )┛

I hope all this build up doesn't end with iruma going back to the human world and the others having their memory erased. I'd be devastated.