FAQ

Most likely, in the beginning he pretended to like her to get information about the Dark Stone society. However, after he killed Fatty Chen and got all the information he needed, he stayed near her because he knew the rest of the society would eventually come to her because she had half of the remains. Over time, he eventually fell in love with her, which is why he didn't kill her immediately after killing Fatty Chen.

The monk Wisdom reveals to Drizzle (in the whispered conversation as he is dying) that the secret of the remains is that it allows someone to learn how to control their Qi flow to heal any injury (as discovered by the Wheel King,) but they must be pure in character (revealed during Drizzle's 2nd fight with the Wheel King,) therefore the Wheel King, even with the remains, is too evil to do it.

This was never fully explained in the film. She stole the remains but never did anything with them. She stole silver but didn't spend any of it. She had an epiphany about how she was being used by the Wheel King from Wisdom, but this was after she ran away. She may have felt guilt during her last assassination, but this did not stop her from killing Ah-Sheng a second time when they met on a bridge. I believe this was an editing mistake where she met Wisdom _before_ the last assassination.

In the first fight with the Dark Stone society, he was outnumbered and probably surprised. In the opening stills, you can see that he was already injured during the fight. One on one, he could easily defeat the acupuncturist, and the prostitute was relatively new and unskilled. He probably could not defeat Drizzle or the Wheel King by himself. Therefore, his ability did not really improve.