On the contrary, we may not be the most powerful but we throw the best parties. (Except for poor Stormrage, Tyrande keeps him on a short leash)
Arcane mage, Destro warlock and/or Disc priest.
While Balance druids and ele shamans both have weapons that are hard to control, idk the actual power behind them.
Gonna have to say warlocks.
On top of their immortal, infinite army, they wield planet destroying artifacts.
What other artifacts have destroyed planets or rendered a land permanently lifeless?