So, my story is pretty much complete, I only want to touch up weak areas. I have two main villains, one of which I think is fairly solid. The other is a lesser bad guy but I still want him to be memorable, and right now I don't believe he is at all.
They say a great villain is often someone you can relate with on some level - maybe he had a horrible childhood, maybe he secretly likes puppies. My problem is that I'm writing a demon, not a human character, and due to his very nature he is completely evil. My thought for a similar character goes to the demon in The Exorcist, who made a fantastic villain because of just how horrible and unrelatable he was. My demon does some nasty stuff, but I feel like his character simply comes off as overdone and maybe even cheesy at times.
Has anyone ever had this problem while writing, and have you got tips? Or perhaps an article you've come across that covers this?