These are extremely beefed up witchys and probably the most dangerous mages in the game besides Lord Dredmor. They can not only raise dead and blind you like witchys can, they can also cast Arctic Vortex from the viking wizardry skill, and Explosive Rune from the Promethean magic skill. The latter is cast on your square, so will not automatically trigger and can be used against the enemies very effectively. They also deal a very large amount of melee damage. Kill as fast as you can and stay out of their sights as much as possible.