Hi,
I know balance is obviously not in the cards yet, but I've encountered some spells that are insane. Number one? Dirge of Cersei.
With 2 death shards I've managed to run around the world, destroy enemy empires, and kill all monsters. The spell does a ridiculous amount of damage. I'm seeing numbers like 68 or 100 at a time.
You should know however that I did stack spell damage bonuses. I'm using the staff she starts with, and I selected several of the 'increase spell damage by 50%" buffs.
I pretty much ran around with her and my starting hero (assassin) and destroyed the enemy with very little resistance. Using troops barely made a difference. I was playing challenging AIs that had Empire ratings much higher than mine- they did not pose a threat. Even in a battle where I was fighting 10 vs 2, I called up Dirge and killed everything in a single turn.
What are some other OP spells/combos have you discovered?