What a great chapter, and arc.
There are many things I could say, but if I could only say one, it's that I think Azumi has finally fully committed to never be happy. It really could not get better than this. A man she loved, that was also a cherished leader that she greatly respected, someone he could see as an equal, the sister was earnestly in on it too, a great future filled with happiness; but she let it go.
If this does not break her resolution to spend the rest of days killing, nothing will.