>>43711645Gen 1 explored that concept already, and afterlife exists in Pokémon. Some may wander as spirits if they have unfinished business, or their trainers haven’t made peace with them.
Kinda like that Snubbull or whatever that saved its young adult trainer from a factory burning down, but got trapped inside and died. The trainer didn’t come back until she was elderly and they hugged it out or something, I don’t know, don’t remember the episode.