One word: [b][i]Bloom[/i][/b]. Also, Nova Bomb with shatter, bloom, and Annihilate, combined with the Axion Bolt Grenade is the pure definition of beautiful, visceral, explosive void AOE damage. No other class, nor subclass has the AOE damage potential that Voidwalker Warlocks do. Don't get me wrong, though. As much as I am one who spends his days pondering the energies of the Void, I very much respect and appreciate those who dabble in the energy projection, and purity of the cleansing flame. Both Subclasses are amazing. It's all up to personal preference.