Lame bait but how about…
Satan comes from ancient Greek Ha-Satan, meaning "opponent" or "adversary"
Christians took off the "Ha" part, and gave Evil a Name
Then decided to give it horns, and the cloven feet of Bacchus/Pan and thus Form
Then decided it was to blame for all their own faults or anything Nature did that was not to their liking, so gave it Power
Congrats, you did collective Spell Casting