I got this to spawn today while doing the Hunter achievements. It did give the prompted text other users have reported. Saying "I will cleanse the rage spirit" spawned "an enraged luggald abomination" which seemed no different than the many other trash mobs in the zone, and like others reported, dropped no loot.
Emote upon spawning "An ancient spirit stands over the glowing pool of magical power."
Edited, Jun 25th 2017 5:09am by Bobbybick