Celestial Beings

There are stories about spiritual beings that exist outside our mortal realm and sometimes cross into ours. Across religions, mythologies and cultures, these mystical entities have manifested themselves in various shapes and forms. Two celestial forces, light and dark, at constant war. We are but terrestrial beings, but let's see if there's anything we can do to help.

Add books you've read that feature an angel or demon as one of the main characters (a main character being possessed by a demon also counts).