the capstone, Embrace the Void should be a toggle instead of a 100 mana spell. I mean 100 mana for another death aura with a low duration?
Just make it as powerful as Death Aura but in toggle form--exclusive to Death Aura but in a set it and forget it configuration.
Or even better, if you don't want to do that, make it JUST a permanent Heal over Time toggle for JUST the Pale Master.