I was fighting a Marble Imler who attacks 10 times when an Imling dies. With my current team I kill every creatures during the first turn and I think that the Imler’s perk is still being triggered. I managed to reproduce this bug a few times by going in the Swamplands as a Monk.
The issue is that even though the Imler is dead, he can still attack, then my creatures counter-attack an already dead enemy which can quickly become tedious.
The monster in question:
Battle 1 (Marble Imler A was already dead):
Battle 2 logs (Mithril Imler died at l.66, but attacks, dodge and counter-attacks happen in the second screenshot):