Won Jin did all of his own stunts apart from the one where his character is kicked out of the window and onto the stairs below. This stunt was performed by stunt man Chi-Chuen Cheung, who was very seriously injured and took a long time to recover.
Won Jin uses his legs almost exclusively in the fight scenes, rarely using his hands and instead focusing on his kicking and gymnastic skills to amaze the audience.
All the hand-drawn illustrations that the character Yuk-shu created in the film were drawn by Kar Lok Chin himself.