Jason dodged the Joker's razor cards easily with a quick flip to the side. It was reminiscent of his days as Robin; the days when he'd use acrobatics and basic combat to take down criminals. Now, he used different methods, but the things Bruce taught him were still a big part of his fighting style.
He continued forward and, just before he reached the Joker, jumped high into the air. Jason descended upon the clown, delivering a kick that he was sure (hoped) would hit. Whether it hit or not, he flipped backward and landed on his feet, preparing to spring towards his opponent once again.