Chang Chen brings a sense of comedy and cavilerness to the role of Lo. He has a Cary Grant, Harrison Ford charm. Beside Michelle Yeoh's, the performance I liked best was Cheng Pei Pei as Jen's diabolical mentor Jade Fox. She only has a supporting role and does not receive much screen time, but when she is on screen, her performance is fantastic. While ferocious in the fight scenes, she plays the quieter moments with Jen as a confused and hurt mother who cannot understand why the choice between her way of life and that of Li Mu Bai is so difficult.
Great actors are nothing without strong roles.
Fortunately, all of the parts in this film are strong. Every character, even the minor ones like the police inspector and his daughter, has a reason for being and motives behind his or her actions. Additionally, the characters' behaviors and personalities result from their backgrounds and are not just predefined constants that the audience must accept. This is very rare in a film. The filmmakers have rightly given their central character, Jen, the most history and depth.