Wandering Exorcist

Although monsters do exist, some of them known as Yokai have to be killed in a certain way : The rite of exorcism. An ancient technique passed through families of mages known as "Onmyouji". Their primary weapons were painted charms made of divine trees. Spells were written on them. Modern exorcists now use books containing their spells without having to rewrite them everytime they cast it. You don't want to know how many perished as a result of a lack of charms.