I'm writing a fantasy story and I wanted to include both monsters and monster girls and I was wondering if it would be legal to do this and publish it to make money. The reason I'm worried is that my concept for the monster girls existing would be that a succubus tricked a god and now there is many kinds of succubi/incubi that way there are still normal monsters as well as other races. I don't know if that is distinct enough though. Any advice would be appreciated.