Now I don’t think Pokémon is sinful, but maybe it is I don’t know. And If it were to be Sinful would it be a Mortal Sin?
Now most people have a problem with Pokémon because it promotes or teaches witchcraft and sorcery.
I have played Pokémon since I was 7 and I NEVER believed in witchcraft, because I simply knew it was a game and those things weren’t real. And the only thing I can see that would be close to that is the Ghost Pokémon. Some Ghost Pokémon can go through the “Spirit world” and can steal life forces. However this isn’t a main plot in any of the games and this description is more in the pokedex (Sort of of the Pokémon encyclopedia)
Now there is one pokemon called Arceus, now it says it created the universe, HOWEVER, it is stated it is a MYTH . So it is not stated that this Pokémon actually did for certain. Also I don’t think anyone would believe that this Pokémon actually created the world in real life.