Quartz

Quartz is a professional con man. He'll pose as a waiter, a police officer, a nurse, anything, in order to gain peoples trust. Once he does he drains their Cor. Magic and promptly disappears. The reason he does this is because of Heket, a malicious Cryptid who coerced him into signing a nasty contract in order to save his dying daughter. The contract states that Heket will heal his daughter, but in return Quartz has to become Heket's servant and feed her Cor. Magic, as well as accept that his daughter won't remember him afterwards. (See, Heket is an ancient cryptid who should've been dead a long time ago, but managed to stay alive by stealing Cor. Magic. Despite this she's still growing weaker and weaker and needs to rely on someone to keep her alive.)