You can name a Pokemon Lucifer. See?
Lucifer actually means something good in Latin: Light Bringer/Bearer.
Luc is a Latin prefix for light, and fer is a Latin stem for carry. So it actually means something good, so it's fine.
Also, another thing:
> "How art thou fallen from heaven, O Lucifer, son of the morning!" Isaiah 14:12
This proves that the Bible infers that Lucifer is a light-bearer, since he is referred to as the "Son of the Morning".
You can also name Pokemon with names such as "Satan" and "Meth". But "Spike"? That's just a big no-no.
Source: The Caterpie I just caught.