A random thought: there is no male or female distinction between Japanese swordsmen (our general Mo Xie seems to have a female sword and a male sword), so swordsmen should be able to switch genders!
Assuming that Xiaowu is not the real fusangshen, but a man-made "god" that can be controlled (similar to Onikiri Baba), the Lord's command is everything to me, and I will definitely do it for you even if I am shattered to pieces. What Hashiri hated was never the same appearance, nor the fact that he replaced Kneemaru, but that Xiaowu was a puppet without the ability to think of his own.
During those days when she disappeared into the long river of history, Xiao Wu had been living very happily. Everything in the past disappeared like smoke, but she was not anyone's substitute. Until they meet again, what kind of sparks will they collide with?