Giritina has no relation to the devil at all! He's base don Anti-Matter this is stated by GF themselves and is in Platinum
Another alternate form of Giratina
Conspiratorial theories aside, it's safe to assume that if Game Freak doesn't reference the myth, you can bet that people will find some way to make a meme out of it.
I will laugh so hard if it ends up being the new Zubat.