Both top and bottom need a buff, all voidwalker trees for warlocks also need buffs. Titans are in a pretty good place but most of their builds revolve around melees which kind of limits creativity.
Bottom tree void for hunters is ok where it's at tbh multiple shots usually means multiple kills or shutdowns and a good neutral game, and top tree needs a buff no question. As for void walkers on warlock bottom tree needs a blast radius buff and they need to throw javelin in that bottom section already. Nova warps handheld supernova needs to stop doing self damage it was a bad idea to begin with and the charge up time to ready the grenade also needs to be reverted. Every other nerf was justifiable. Also either give the small novawarp blast a little bit more radius and damage, or lower charge time for the large blast. Top tree nova bomb is A+. Lastly both void hunters and warlocks alike need some better grenades either buff some of the ones we have or change them. Nobody uses axion bolt, and few and far between think the grenade choices for those two classes respectively are any good the best grenades are the vortex and void wall. And while void wall is pretty good for catching people behind cover vortex is only good for cutting off a lane and barely that cause people run right through it more often than not.
Well titans can mix it up with Ashen wake instant kill grenades. But Nova bomb is a at least a very good super. Nova warp could definitely use some work but nightstalker is undoubtably the worst of the void classes right now.