I don't think Pokemon are anything to worry about.
It doesn't matter what deep corners of the imagination and personal knowledge fed the creativity of the designers of the little critters in that popular Japanese role playing game. Maybe this designer saw this in a book when he was young. Maybe that designer saw a picture of this-and-such while on vacation in a neighboring Japanese city.
Unless the game *itself* is leading children into devil worship, wicca, etc. -- that would be a problem.
Have you actually played Pokemon? Or even watched anyone play it? Or watched the cartoon?
Remember "reefer madness" in the 50's? We look at it and laugh now.
I remember when I first heard M.C. Hammer "Can't Touch This" I thought it was evil because it seemed to be "rap" and because it had a strangely compelling, hypnotically attractive background music. Now I know it's pretty harmless hip-hop that stole the melody from another song, "Super Freak" and was sung/danced by a one-hit-wonder who gave lots of lip service to Christianity, being good, and "say no to drugs". In short, as a 12 year old I was ignorant about it at first, and as soon as I actually looked into it, I found it to be quite harmless.