I always laugh when people talk about devil worship. If you firmly believe that heaven and hell exist, why exactly would you worship the devil? It's not like he's going to reward you. Maybe you get a slightly less terrible eternity of pain and torture?
On the subject though, if you look too deeply at Pokemon, it's a pretty cruel world. It's not going to turn a kid away from religion though. In fact the mechanics of evolution in the game could convince a kid that real life evolution is ridiculous and impossible.