I just find Warlocks sort of lacking an identity in this game, or at least an identity that fits my playstyle. Hunters have their blades, and Golden Gun. Titans have their bubble and slam. Warlocks have self-res, and can shoot an AoE. They're essentially mages with very little mage in them. Diablo 3 my Wizard could self-res as well as shoot a zig-zagging electric balls, make it rain fire and ice from the sky, create a singularity, summon Serpents that shot out different elements. I picked a Warlock expecting to play a space mage, and all I got that was a large explosion that I hardly get to use because self-res is too enticing as a safety net. Though to be fair I find all the classes lacking in some capacity, but Warlock just hurts more since mage is the class I almost always play nowadays.