I hate pallies that get merc's in on it too. I believe you can get 6 auras. Exile (Defiance), Beast (Fanaticism), Doom (Holy Freeze), Bramble (thorns), Aura of Merc (Might), Aura of you ( I would go concentrate).

It's really retarded the way they can do that. I'll have to test the effectiveness on Open. (Get the 6 auras going)