The "Karas" is a human with supernatural powers that polices the spirit and demons that choose to live in the human world. He is mostly going after one demon and his followers that have to drink human blood to remain here in human form. Also, if I remember right, the current Karas has to fight with another human that is destined to be the next Karas. It kind if has a "Mech" feel because the Karas can change his form into a car, jet, or just about anything mechanical.