Thanks for the all the help on this question.
As an extension to this question, I'm just trying to get my head around the Bury errata and how it effects Bete Noir.
Say for example, Bete is on 4 wounds and is hit by an ordinary melee/ranged strike which causes 4 wounds. This reduces her to 0 wounds and so would kill her. She uses Slow to Die and uses One With the Night to Bury and fully heal her. Can she still do this with the Bury Errata?
The way I was reading the Errata and subsequent discussion for Bete was the only thing it stopped her doing was keeping up Depraved Tactics for several turns, but I was told differently in a recent game.