Oh, I am
all about this.
I don't remember if I've ever RP'd Desmond with you or not? But if not, he runs an organization specifically dedicated to helping people who have fallen into Evelon from different dimensions. He could be a main player in such an RP, or a background presence.
Felix can cross dimensions at will, but has decided he likes Evelon and is staying here. He could try to help people find their way back home, or just provide a friendly ear.
Dinni here traveled to this universe as an egg, and doesn't remember his home. But he's currently collecting "monsters from across the cosmos" (IE, Pokemon and related customs) to participate in a big tournament to determine the greatest monsters of all! (Hooray for obligatory tournament arcs!)
He's not from another universe. He's just a cryptid hunter. I think it'd be most droll, though, if he mistook travelers from other worlds as cryptids.