I think this is a fascinating subject and I am glad you brought this up!
Personally I think that a creation wizard would be amazing. Especially with my imagination, being a green lantern sounds like a very fun way to destroy everything. Making giant zombie dinosaurs...no big deal (as long as you want giant red or blue dinosaurs). Imagine creating a giant pogostick to just leap over the enemy walls! Although after that, a necro wins by far.