I tried both Ony and MC with 5 shamans.

Ony: Phase 2 is problematic to say the least, the fireballs still do a lot of dmg, might be doable with the heroic badge fire resist gear?

MC: Made it all the way to Lucifron and Gehennas, the hound packs at Luci are quite difficult to kill all at the same time before the bites stack up on all your guys. You can pull Luci without clearing any of them if you are careful but not being able to decurse almost guarantees failure (same with Gehennas - you just cant heal through the 75% less healing curse he puts on). Got two BOE epic rogue belts and hunter belt, so that was pretty cool