You cannot hide from his AE, hard keeping the entire grp healed if you only have a cleric and shaman.
Killed him yesterday...grp was 65 sham (me) 65 pally 63 monk 62 wiz 59 cler... The 59 cleric gated cause was oom when overseer was at 60life, the 62 wiz died from AE.
So i kept me pally and monk alive with quiscence (one of the most powerful shaman spells) I estimate him to have about 80k+ hps, he was about a 15-20 min fight... real problem is his 50% slow (which cancels spell haste), the 500DD AE (-300 to fire) is not much of a problem with a good healer..
dropped arms x 2 on first kill, second time dropped arms and guants... so safe to say he drops 2 items a pop..