Taken

(AU) Rin, the youngest child of Satan, is captured by the exorcist and they plan to use him as a weapon. Yukio soon rescues the boy and grows to care for him. He tries to keep him hidden from both Satan and the Vatican, but it's hard when demons, exorcists, and a group called Witches is after him. But who are the witches and why are they after him? (I'm bad at summaries)