This topic may contain spoiler
Ok so
The black hair knight is faking all his action now cos his father want to do something bad to Lanka. The man at the last panel is Lanka brother but he is not the real one. He is a fake made by the black hair knight father to keep watch of Lanka in a way and the bad father want the fake brother to bait Lanka to him. So all action by the black hair knight is to protect Lanka. As the only way he can protect is to hurt Lanka to show the fake brother aka spy that he does not treasure Lanka so they will not increase the spy or any other shit to try hurt Lanka.
It been a long time so some info might be wrong but I assure that the black hair knight is good and the fake brother is bad but at the end he did use his life to also save Lanka
i'm so lost if someone understand even a little bit what's happening pls tell me