I never use Medica2 on pack on monsters, I spam divine seal + regen, or Divine Seal + regen, and after 2 or more holy, depending on how can aggro the tank, trying to keep 2k mana if shroud is on CD after every pack of monsters (and I do a pack without dpsing to regen some mana, or with only 1-2 holy), trying to put stoneskin on the tank also beetwin each pack of monsters, begin to cast it when you see the last monster dying.

I dont why medica 2 (ok, from the dragon that does aoe, yes, you need it, for the other, never)