i know there is a lot of styles in the crane and the praying mantis and ba gua. then what types are there? and what is the most powerful one??
Well... you seem to have two questions in here. First of all, the crane and praying mantis are both stances used in internal (Weija) and external (Neija) Wing-Chun (Kung-fu). Second, Bagua is one of the internal styles. External styles are more powerful for fighting styles.
