this hasn't been fixed yet. i'm insta-dying while fighting Luminescent Spores in the Sanctum. zero injuries; spore not only insta-downs my hero, but outright kills him when he has zero injuries at the beginning of the fight. as the first poster stated, i imagine this bug gets a lot worse later in the dungeon.
seems to be related to Lengraths Teachings or Safeguard being cast by the Spore, and getting charmed. i think charmed targets outright die when the charm is up.
i'm a bit amazed this game-breaking bug hasn't been fixed after so many months. instead of enjoying the dungeon, i basically have to suffer by letting my lvl 20 heroes die, looting them, and retraining them after each Spore encounter (i sure as hell aint redoing these fights). weird how this bug isn't discussed much.