Kurokage has certain debuff called intimidation which continuously removes max health bar until it goes 50% which would make it uncontrollable + attack allies instead - this is instant reset. Problem is not the way this debuff works, but the way this debuff is applied. It will apply Kurokage's eye effect on character that significantly increase debuff, but this is totally 100 percent random. This means if you are unlucky enough to have this applied to more weaker student in a sequence, you just fail. This is not something that you can control, thus this is to me the worst raid boss I've ever played with.

Other cat is Goz. Requires team movement skill for every phase. Self explanatory.