Tried him with a group of 95s... his AOE wrecked my group pretty hard, about 40k AOE, and apparently rampages, unless his rampage was the AOE hitting my ranged. Might be able to do him with 2 healer mercs, but didnt bother trying again. Probably a cake walk for lvl 100s who can survive the AOE better.
He popped for me and was red to a group of 91s (Sk, Brd, Nec, Wiz, clr mercx2). Since it was close to the end of the mission, group was self buffed between 50k and 60khp. SK tanked under deflection to start. It was an "easy" start as the AE dropped all to about 50% and the mercs could heal over it. Unfortunately, the group DPS was too low and the SK took a spike 106 sec into the fight ending our try with him at about 75%. GamParse put our DPS at 9-11k depending on log.
Other spells cast: Bleed Essence x1 Decaying Venin x2 Mortification x3 Reaping x4 Scent of Nightfall x1 Petrifying Gaze x5
Spawned today in the second heroic mission from Marle. Fairly straight forward fight, wild rampage but not too often or too hard, otherwise tank n spank. Dropped boots of latent ether and a 5 base dmg, heals targets target for 420 weapon aug