The 12% wipe. If we time Rain of Fire right, with everyone outside, heroism (more boss time if Infernals go down fast), more gear, everyone alive, we can kill it before second Rain? Or as it's incoming at least.
If yes, we can burn all healer CD's for the first Rain which should make it easy. Heart of the Wild, Treeform, Ring, Devotion Aura, Wings, Tranq = unkillable. Assuming we deal with mechanics obviously.
The 12% wipe was our best attempt, but still messy. Tagan was dead a good while and Toban died too. Even then, we got the boss to 12%