Ousen didn’t think the battle would progress so quickly from the beginning. For one, he didn’t calculate that the Hi Shin Unit and the Gyoku Hou would get sealed off so quickly. And second, Shibashou’s strength goes beyond Ousen’s expectations. On of the chance that Ousen loses this battle, it would be due to these two factors, and Ousen would have to acknowledge that Riboku outmaneuvered him.