Depends what ur doing. I would go bal Aura for offensive capability, but i would switch to symbol of wrath if i was going defensive. Stops warriors attacking you for a bit, or they take a good deal of dmg.
dude! symbol of wrath is 5 enegy and balthazar aura is 25e! after casting balthasar you wont have enouth energy for ANYTHING. balthasar is for monks and even them cant always afford it!