Well, if he pneumas just keep your distance. If he's FO type cloak so he has to move near you, thus going out of pneuma.
If he isn't wearing RSX or GTB, jupitel thunder him away; if he's wearing eithen then AV should rape him once he moves out of pneuma to asura/ruwach you.
If he snaps near you just keep up AV spam (AV AV AV, attention concentrate, cloak, AV AV AV = near-infinite spam); try to time your bursts with his snap out of pneuma. Make sure to always keep moving; especially if he's asura type. If he's near enough to asura you (and is asura type / hybrid); try to switch to orc lords to piss him off if you can. If you're a gypsy, use the slowdown song a lot whenever you get the chance.
Most importantly, keep your distance at any cost, and cloak a lot.