Here's my rule about creating supernatural creatures in a story-make up your own rules. Just stick to them. It would be very easy to research some mythological data and use these monsters, gods or demons in a usual way. Use just those same old boring perspectives. But how much fun is that? You must free your writing mind to all kinds of possibilities. Go beyond your perspective of religion, the supernatural or demons of your own upbringing. Research other cultures and histories. Study different ancient religions and philosophies. Read other novels of the types of fantasy or horror or science fiction that interest you. You need to do this to stretch your mind. I like making up my own dark gods and demons, good gods, monsters, spirits. After all, I am the creator of my fiction fantasy universe, so I do what I feel works best for me and my story arcs. Remember these things are also part of the flesh that makes up the culture and society of the characters. It's al