He was adorable back then. Now, he's just hot and masculine.
Ok, I'll try my best with the synopsis, but I skipped over the boring, non-Wallace parts, so I may not have the complete story.
Ni Shui Han centered around a cat and mouse chase in which the antagonist, Gu Xi Zhao played by Wallace Chung, was the cat, and the protagonist, Qi Shao Shang played by Julian Cheung, was the mouse. On a chance encounter, Qi met a loyal general who asked him to protect an important sword, called the Ni Shui Han sword. The general unfortunately did not divulge to Qi why the sword was important. Qi accepted the sword and soon found himself the target of an assassin sent by the corrupt and evil Prime Minister Fu. Unaware that Gu Xi Zhao was an assassin sent to kill him and retrieve the Ni Shui Han sword, Qi initially befriended Gu, finding him very intelligent, capable, and heroic. Unfortunately, not long after, Gu revealed his true colors, and hence began the cat and mouse chase that spanned 40 episodes.
I found the first 2-3 episodes of the series rather artsy-fartsy and not really my cup of tea. However, once Gu revealed his true colors, the series got exciting. The entire chase was extremely exciting, with the very intelligent and resourceful Gu always almost accomplishing his mission of killing Qi, only to be thwarted by something or someone.
Wallace was the surprising underdog in this series. I don't think he was very popular or well-known back then when this series was made, but after the series aired, I heard that the tieba forums exploded with discussions of his character and of him. Even now, 7-8 years after the series aired, fans are still making new MVs of his Gu Xi Zhao character! He stole the show from Julian Cheung with his very impressive rendition of the very complex, very evil, and yet sympathetic villain, who craved fame, status, power, and yet in the end, realized too late that what he really wanted was to just simply be with his wife, to love her, to live with her in their little cottage.
Because of his most impressive rendition of the suave yet extremely evil villain, all of Wallace's parts were exciting. Julian's parts, on the other hand, were boring and bland in comparison. And because Gu Xi Zhao's love affair with his wife was so bittersweet, they became the more popular couple, whereas Qi Shao Shang's love with his female lead took a backseat.
Character synopsis on Wallace's character, Gu Xi Zhao
Gu Xi Zhao was an intelligent and proud man from very humble origins. He met his wife, Fu Wan Xing, during one of his flying dagger performances in the marketplace (his way of panhandling for money). He was asking for a volunteer in the audience to be his target. Wan Qing, who was suffering from a broken heart at the time, agreed to be his dagger target, in hopes that Gu Xi Zhao would miss and kill her with one of his daggers. Of course, being the good martial artist that he was, he did not miss. Everyone in the audience clapped, very impressed with his flying dagger skill - everyone, that was, except for Fu Wan Qing. As Gu Xi Zhao rushed toward her, all smiles, she slapped him, asking him why he did not miss and kill her. As she ran off, he followed her, already besotted with her beauty and grace. He trailed after her from that day on, already in love with her. Eventually, he won her over with his persistence. They fell in love and married. But her family never truly accepted him, scorning his humble background, mocking him for even daring to love the extremely beautiful Prime Minister's only daughter, a young woman leagues above him in society. Proud, he vowed to not consummate the marriage until he could prove to Wan Qing and her family that he was worthy of marrying her, of loving her. He promised to make a name for himself in the martial arts world, to become someone with power and status. And hence, he turned evil, killing innocents at the bidding of his villainous father-in-law, in order to win his father-in-law's favor. Even when his wife begged him to stop his evil doings, he continued, believing it would be the only way to prove to everyone that he could be a suitable husband for the beautiful and rich Fu Wan Qing.
spoiler below!!!
Sadly, Gu Xi Zhao failed to understand that Wan Qing loved him, for richer or for poorer. To her, he was already a hero, as long as he lived as an honest and good person. When she committed suicide in the end, he finally realized, too late, that power and status were only empty prizes when the only person he loved most in the world was no longer by his side.
He survived in the end, but his fate was probably worse than death, as he had to live on alone, in sorrow and regret, without his beloved Wan Qing.