How many movies have Billy Tang Hin-Shing and Julian Cheung collaborated on?

They have worked on 8 movies together! Their first movie together was The Legend of Lu Xiaofeng 3 (2007) while their highest rated movie together was The Legend of Lu Xiaofeng 9 (2007). They have not worked together since The Legend of Lu Xiaofeng 10 (2007). They are most known for their action films together.