Exorcist necromancer

An exorcist, someone who rids the words of ghosts, someone who lays the dead to rest, the antithesis of that is obvious someone who raises the dead and brings them back into the world, a necromancer. What if you awakened as one of the lucky few after a school tragedy? And what if in a world of unique exorcism techniques, you just happened to awaken to the powers of necromancy?