If the title was meant to relate to one person, then I guess it was meant to describe the split personality of Lap, a ruthless character who as a police inspector with high ambitions, chose the easy way to attain them. He compromised his police duties in colluding with drug dealers, and married into a rich banker's family. In the process of committing crimes and covering up, he destroyed both his and his in-laws' families. He has his warm heart moments when he displayed his undying love for Suet, besides his love for his family members (or just being convincing at the right moments).
Daughter, Chris (Cheung Ho Yee) was finally steady with a junior executive in the family bank, after a few years of sleeping around with every Tom, Dick and Harry, including Lap;
Tsui Kin (Bao Fong) and wife (Bak Yan): adopted son, Tsui Wing Pong (Adam Cheng)
Son, Tsui Ka Lap (Gallen Lo) married Grace (Astrid Chan);
Daughter, Tsui Ka Yi (Wallis Pang) married an ex-police informer (Cheung Siu Fai);
Fong Hau Yung (Nadia Chan) – wooed by Kin, but Hong, though a good friend of him, deliberately sent her to their bank's Shanghai branch so that he could woo her without being distracted by Kin. He even deliberately left out a message to be forwarded to Kin. It was much later that this fact was known to Yung, who is still very much attached to Kin. This act of betrayal of a friend, and his failure to inform others that his uncle was killed by Lap, showed a weak and confused character who could have prevented further damage by Lap.
Fong Hau Yung's elder brother (Wilson Tsui), a dubious character who always get into trouble with the law, inadvertently implicating Kin when he tried to be helpful.