I don't feel like there's gonna be any significant DRK changes in 5.2 tbh especially with something like adding or reworking abilities. My only real gripe with the job now is Delirium is quite literally just Inner Release but without the big flashy number for my lizard brain but defensive wise DRK is very good and doesn't really need anything else.

Also I saw in OP something about Sole Survivor and while that was a cool looking ability the new Abyssal Drain does what you're asking, just less effective on single target and no MP (which really isn't needed and Carve and Spit already does that).