Unholy Death Knight feels so bad to play with right now, we have so many dead talents in the talent tree, and we don’t even use Gargoyle because it’s design is just a massive dodo.
My suggestion for Gargoyle is to move it as a choice nod with Unholy Assault, and Gargoyle should be redesigned to synergies better with our rotation. What they can do here is to make it so we raise 3 Gargoyles to bombard our enemy target with each of them having a chance to apply a Festering Wounds, in addition, why not slap on a increased chance to proc Sudden Doom while Gargoyle is active and make it so our Undeads also deal increased damage while Gargoyle is active. I think that is way more interesting than mashing your face on the Death Coil Button.
Also can the entire side where All Will Serve be changed, i would rather see the return of Raise Sludge Belcher after you have talented All Will Serve. Not only does our Pet get improved skills, but they could make it hit harder to give some more focus on our minion damage profile over Clawing/Death Coil.
As for Ruptured Viscera, this talent is absolutely bad when we are not raising undeads all the time. My suggestion here would be to add a new passive that makes it so when we have talented in to All Will Serve, we can use Dark Transformation on it as well. Just turn it in to a giant Bone Lord that use Bone Storm that charges in to the enemy once every time you use Dark Transformation on the Skulker.