I had Shadereave’s “Eternal Servitude” buff up (2 turns remaining, little green skull was visible, and Marjana, who wasn’t hit, still had the buff after that turn). Onyx did a hit three, knocking out two of my surviving heroes. Neither of them resurrected as a draugr. Apparently, his “remove buffs” is processing against dead heroes, which is unusual — normally when the hero is dead, the rest of the special doesn’t happen. I wouldn’t have won the battle anyway, but either the card needs to be clarified or the bug corrected.
Presumably, the same thing would affect Marie Therese, possibly Tyr and Atomos. I don’t have them, and don’t have enough heroes left to even try getting any farther.