Just remarked this as the boss I was fighting (rat ogre with Invincible + Implacable) kept healing itself at an alarming rate.
Seems every time a Khorne champion came in range with him, it’s health bounced up ~12% of its max HP, and obviously not declining when said champions were killed.
I don’t remember this being an intended effect of this curse, and having an invicible monster regen back from almost killed to 50% in seconds is a horrendous thing to see.