Who is Tang Wenting / Bill Tang from Dragon Bones: A Novel and what is their importance?

Tang Wenting is Xiao Da's right hand man. Throughout the novel, he repeatedly appears where Hulan is, making her believe there to a link between the All Patriotic Society and the deaths of foreign archaeologists. When David meets him as Bill Tang, a genius computer programmer from the States at an auction for an ancient ruyi, it becomes clear that the leader of the All Patriotic Society seeks to obtain the ruyi, and that the ruyi is believed to be the scepter of Da Yu. Tang attempts to kill David, as well as Stuart Miller, in an effort to obtain the ruyi. In the end, Tang is captured.