Oof, now I'm beginning to feel guilty. I have a custom CC I'm writing, that I haven't released yet, because the Warriors, Shamans, and Monks aren't ready... but everything else is, including druids and warlocks. I am reluctant to release it until it's a complete set.
I chose to open with 'Rain of Fire' for destro warlock. My son questioned my choice of opening move, and I stated 'As a destruction Warlock, there is not a single moment that goes by, that would not be improved with a rain of fire coming down.'
Have you ever spammed that spell until you ran out of mana? Glorious! Instant cast, low mana, and awesomesauce.