AKA: Ogre Mage
Oni are unpleasant fey creatures responsible for disasters, diseases, and other unpleasant things. They are giant creatures, blending elements of oxen, tigers, and ogres, into a fearsome visage that telegraphs their ill intent. They frequently wield iron clubs.
Oni are capable of powerful, deceptive, fey magic: flying, turning invisible, causing darkness, changing form, regenerating, charming, causing sleep, hurling a blast of cold, and transforming into a gaseous cloud. Many of these abilities are active more-or-less continuously, with sleep and charm being used outside of combat, and a blast of cold being used as a last resort. Frequently, enemies who expect them to be simple brutes due to their size and bestial appearance are sorely mislead. When forced into raw physical combat, the oni attacks with their club (and the occasional blast of cold), displaying a primal strength that shocks foes who expect them to be fragile mages.
Oni will occasionally press a gang of bakemono into service underneath them, though these alliances rarely last long.