The Jade Faced Assassin

The swordsman Zhang Zhen is injured in a misadventure and rescued by the Eldest Sister of Changchun Sect, who has a crush on him. However, Zhang falls in love with the maid, Yue Nu, instead and conceives twins with her. The couple is killed by a group of evil pugilists later. The Eldest Sister is angry with Zhang Zhen for not accepting her and plans to make Zhang's children kill each other as revenge.
The baby girl is saved by Zhang's friend, Lian Lan Yan, while the male infant is taken away by the Eldest Sister. Lian Lan Yan encounters the Ten Villains when he passes through Villains' Valley. He is overwhelmed by them and knocked out in a fight. The baby Xiao Lu Er is taken away by the Villains, who surprisingly do not harm her, and instead intend to groom her to become the greatest villain ever. Eighteen years later, the twins meet each other by coincidence.
(Source: Wikipedia)
~~ Adapted from the novel "Juedai Shuangjiao" (絕代雙驕) by Gu Long (古龍).