Only one I know of is the one you get from CoTF achievement. Need to beat Burn Out in Argin Hiz and that other mission in the tower...names escaping me.
Found it, Staff of Viral Flux. Though, at this point, does a 15 pt debuff really matter all that much?
Good for pulling. And for mass pulls of very grey mobs you can multibind it with cycle through nearest npcs. Run around spamming that key and you will have them all follow you.