The Swordsman 2

Blademaster and his martial arts school decide to retire to a distant mountain. Before leaving, he visits his friends, a tribe of snake-wielding women warriors. He finds that they have been attacked, and their leader, Princess Yin Yin, toward whom he has some romantic feelings, has been abducted. The attacker is her evil uncle Fong, who, years before, overthrew Yin Yin's father and took over their sect. Fong also has possession of a sacred scroll which tells how to achieve ultimate martial arts power.
Blademaster decides to help Yin Yin and her imprisoned father, and his romantic complications deepen when his childhood chum and Yin Yin are joined by a new rival. Blademaster thinks she is an innocent village girl he has saved, but in fact, she is Fong! The process of gaining ultimate martial arts power requires self-castration and transmogrification into a female form.
~~ Adapted from the novel “The Smiling, Proud Wanderer” by Louis Cha.