I this world, humans and mystical being live on the same place. Though, dark being like demons, fae, vampire, werebeasts, and etc. still prefer to live hidden among the humans

Christian is also included, he is the king of vampire. He already lived through many centuries, mostly hiding his identity and living on the place where humans can't reach him

But there are few exceptions, he still needs humans as blood source, and you are choosen to be his blood source