I love that touch of death artwork EmeraldTiger!
I don't like the idea of this being in death. It means that it will have to be balanced for death triggers and this will probably nerf it to the point where it is only usable with those triggers, especially Bone Wall. Taking it out of Death will give it more variable usage.
Given that this would end up being very OP with maxwell's demon. Grip of Death could even a good standalone spell