Was it a standard practice in the wuxia world that people become monks or nuns after realizing that they had done something really bad?
For the exception of Cheng Kun, Xie Xun from HSDS became a monk after killing loads of people to repent
Xiao Yuanshan and Murong Bo became monks after realizing that what they did was wrong.
Princess Changping became a nun after the fall of Ming Dynasty
Li Mochou became a nun after her husband left her