The Sword from the Sea 2

A powerful sword is hidden underwater and guarded by a sea monster. An acolyte is sent to find and retrieve the sword. Along the way, she meets Cheung Ying Tsoi and two fish-selling siblings. The brother, Kam Hoi (played by female actress Lee Fung Sing), is temporarily endowed with kung fu powers by an old crone who wants him to bring back her son and daughter. The sister is cast under a spell by Sek Kin, given a new identity and becomes his tool to obtain the sword.
(Source:
HKMDB by dleedlee)