I have no idea what their actually called,but their the Mages that shoot the Black Smoke/Swirling Spells that keep doing damage to you once you've been hit. They start appearing on the Second Survival Challange (The Hard version of it) and the Mission where you go with the Wizard dude (i think it's #12?).

Anyways, the problem is, that on said mission, these accursed mages are on the rooftops and they spots you at an insane distance making it even worse to deal with them, i came in as the Huntress with Sniper Arrows hoping to take those guys out from afar, but it's a no go either. Ideally, the Warrior would be the best option, but those guys up in the rooftops ALWAYS nail me when i'm dealing with the other goblins and ogres :\

Any helps? :(

Yeah, i found that the Archer class works better against them, what i i finally did in my case was avoid them and when i returned, i had a checkpoint activated already and i had the good fortune of encountering them on the ground floor, so i just whacked them out :)