I so meant to reply to this… but I kept forgetting when I was at the keyboard. *Facepalms*
Yes, absolutely. I think it is totally fine to have a world that works differently from ours, but just so long as we know that the power isn’t representing how demonic powers work in our own world. I believe there should be an ultimate power source that defines right and wrong (at the very least). I would be very squeamish about powers that have a black/white side.
Well… As far as how to portray evil power in particular…
Some tips I would give personally (and this is once again something to pray over and decide where you stand on).
Don’t spell out the spells, yes. Be very careful with spells… I won’t say never use them, but I will say that I personally would never use them in a good light (just in my own fiction).
Don’t be too graphic. This sort of rides off what I said in the first tip, but just beyond spells be careful of the details that you use.
Be careful of the fact that magic is seductive, so be extremely cautious of where your characters get their powers especially.
Always try to point your reader to truth of our own world.
I wish I had more specifics, but all I can really say is to know what you believe, why you believe it, and to spend a lot of time praying and reading Scripture. This will help you tremendously as you set up your world in light of truth. I hope this is helpful!!
Tek an ohta! Tek an cala!