…something like wow’s destruction warlock (specifically WOTLK edition)
Spammable chaos bolt doing massive ST damage,on hit if there are more targets it bounces off dealing % less damage with each hit.
As well as AOE stun
Some self buffs
Or even maybe something like Demonology warlock (also WOTLK edition) with Metamorphosis - (You transform into a Demon for 30 seconds. This form increases your armor contribution from items by 600%, damage by 20%, reduces the chance you’ll be critically hit by melee attacks by 6% and reduces the duration of stun and snare effects by 50%. You gain some unique demon abilities in addition to your normal abilities)
Basically anything that doesn’t involve 3 meta abilities almost every Acolyte build requires (seal,reap,transplant)
I predict Curse-based and firey, shadowy, life-drainy, and with singleton (you need to chose only one) large (primalist kind of size) pets of various breeds that have different buffs and abilities that will complement certain builds. Yeah stole that from WoW. Voidwalkers etc.
I think Warlock is going to be heavily based around curses and possessions.
I also think it will be the other mastery that has a touch of the void to it. Not full on like Void Knight but it’s the only other one I can see being a little ‘corrupted.’