Players are always depending on that skill in order to kill someone or inorder to win. Its unfair bec. Even if your high HP still it can be lowered so fast with the skill percent/damage/hp/. and The battle power/potency must play an important role with Toxic Fog. Meaning the Higher Battle Power / Potency the lesser chance to be toxic fog by lower battle power. I notice that even if a 360 battle power player vs 300 battle power player still the 300 can toxic fog the 360 in a maximum chance, about 90 percent hit rate.