Responses
I thinks it's mostly because he hasn't used his chi in a female form. He's used to channeling it in a male form so maybe the sudden difference in gender blocked him from using it. I could be wrong though.
Not only that the way men and women use their muscles are different. Men use majorly shoulder and back muscles. Women use hip and leg muscles. He would need to be accustomed to that type of fighting style
Um really? I know that females are physically inferior to males in that respect, but seriously why does Kuroumaru have THAT MUCH WEAKER. Plus she was pretty Y_Y. RIP I hope he chooses to become a female without the repercussions in the lack of strength compared to her male version.