I have a demon (Jhora, Rakshesha), which has a very attractive female human body who has to drink human blood to survive. It was banned from the city where the other demons live.
Jhora is very intelligent, seductive and very manipulative. She can control almost every human being and has the power to rule companies, countries, and everything.
In this world all creatures that are non-human and completely fictional in our world, such as vampires, golems, etc. don't live among people but on their own. Why?
Most of these creatures are strong and intelligent enough to protect themselves easily from human police or government, some of them could be on the top of society if they wanted. They could live a life with all of human pleasures (which my Rakshesha really likes). So why shouldn't they do that in this world?
Remember: She is highly intelligent, so no police would ever discover her demon form.