Because

Leonel blocked one blade, and the second cut into his chest deeply, lodging itself into his ribcage and almost ripping down and all the way through. 

A flicker of surprise flashed through the man's eyes. The blow hadn't been blocked by Leonel's bones, but rather his heart. This was the first time he had ever seen something so astonishing. 

The pain shot through Leonel's body like a spike. He had actually been outmaneuvered. 

Sure, it was because he was trying to grasp a style he had never seen before instead of using his own techniques, but it made his rage flare up again. 

'What is wrong with me? Focus!' 

Though Leonel said this, he knew what the problem was. He was becoming irritable because of his fatigue.