That is what is called a whiff, whiff is when you fail to connect an attack. When your opponent enters rage mode, he will gain access to his Rage Art. He can only use it once and it is when he's low on health, it's a high-risk high-reward situation. If he connects then he gets a ton of damage from you, but if he whiffs like you block it or he just misses, then it is the perfect opportunity to launch and do a combo. But that is when you feel like you got the basics of the game, I advise you to throw after a failed Rage art as it is guaranteed and the opponent cannot break the throw. You know when you got him when you see a quick white flash, that means it is unbreakable.