This hype is big on this one. We were waiting for the best of the Ten Bows to eventually appear but this is an entrance, holy lol. Zhao's fury is already unleashing. Ouhon is taking the harshest battlefield (Hon Sama big W), Mouten and his army are probably gonna show something crazy, Shin is guaranteed to shine big.
As for Ousen vs Riboku. This might be where Ousen equals or surpasses Riboku. After all is this is Zhao's final war and the guy is in for the revenge and is extremely confident that he'd beat Riboku now.
However...if this is truly Riboku's last hurrah to this manga, Hara can also hype him further than he did before, like an almost invincible commander that falls due to a factor of circumstances. Ousen might show himself as a true equal to Riboku now but it's likely that his (and Zhao's) fall will come down to many factors. There's history and all that. And maybe in the manga Shin will indeed get Riboku's head (get the kill, I mean) although it won't mean that he has surpassed him as a general by any means.