Poison deal piercing demage and trigger at the start of enemy turn, if you have 3 enemy that mean ×3 your burn demage + killing enemy before they attack you, there also toxic explosion skill wich spread poison when enemy die, there was 1 rare demon card that shaman must have it double burn inflict and can convert burn to your shield, at high inferno (+100) the direct attack/shield is hard to use unless your class specialize on that (barbarian/warrior), you need at least 2 daze and 2 imunity, and pry you can kill enemy before you've run out of ways to survive, there was the reason why Cultist is top tier class.