Zerker, Shugoki, Highlander and im sure a few others have super armor? Hyper armor? Whatever it means on certain hits enemy hits cannot stop theirs. Example zerker is doin his chain shugoki goes for a certain heavy. The zerkers hits wont interrupt the Shugoki's heavy. You can tell these types of moves by keeping and eye out for when the other character blinks white. That signifies a hit that wont be stopped by anothers attack. So just learn to look out for those on certain characters and either dodge or parry or block them. Also zerker has the same thing so if your going into a top heavy and the other guy is too but you will live and he will die. Do the hit regardless.