Dude Ousen is looking like the biggest fraud on this manga, i know you all are blaming Akou for this, but it Ousen allowed it to happen, he never issued any orders to course correct things, he saw Akou jump i and bite the obvious bait, and went with it
Even if he pulls off some bullshit with this retreat of his, it still costed him his most closest generals, this is such a poor display for the strongest strategist of Quin, specially, since he fell for a frankly lazy scheme, the kind of stuff that was meant for simpletons like Shin and Ten
This is all on Ousen, if you tell me that he was asleep for the whole campaign, the story would have remain unchanged, i am calling him the AFK general from now on