Board Thread:General Discussion/@comment-24.182.147.198-20140220214721/@comment-25268225-20140404164056

Conjuration. Especially on high difficulty levels, with the same amount of magicka to cast three or so fireballs you can conjure a dremora lord that does an incredible amount of damage on most enemies... And draws the enemies attacks away from you.

But of course, having enchanted gear that negates the magicka cost of destruction spells and dual casting with impact perk is easy-mode all way through the game.