DOMD '84 introduced a few characters into the story who were not in the novel, but I wish they had been.
1. Captain Ching: A police captain in Yangzhou who was friendly with the Wais and was secretly a member of the Heaven and Earth Society. He tried to save the Chong Family from being accused of anti-Qing, pro-Ming plots, but was ultimately killed by Obai's agents. He lasted only one episode, but had some memorable moments.
2. Takala: A capable official completely loyal to Emperor K'ang Hsi and the Qing Dynasty. Where Wai Siu Bo was the wildcard that K'ang Hsi used when he needed an unpredictable element, Takala was the one whom the emperor turned to when he needed someone competent and reliable.