I think, the great thing about Devils & Realist ending (talking about the manga here, obvs), aside from Willian/Dantalion becoming the kind of cuasi-canon that’s actually canon Clamp-style (that was fckng amazing too), it’s how everybody after stabilizing the situation on their realms, goes to William at his graduation and they tell him they’re gonna follow him to university and on his journey to become an authority in his world, in the human realm. It wasn’t really said, but I think it had that implication and I like that headcanon; William helped Heaven and Hell a lot and he made friends with their new leaders (and a boyfriend too lmao) and so they’ve come back to him so they can still be friends and now help William attain his own goals. And that’s fantastic ^^