Lang Qianqiu is a god of the East and the last one alive of Yong'an Kingdom direct royal bloodline. Former Xie Lian's student (who at the time took the position of Yong'an Guoshi) who wrongly, but for good reasons, accused him of massacre of his family and as revenge sticked down into three-lid coffing without knowledge he was immortal as a result of which Xie Lian spend there whole century. After more than 700 years it came out that the one responsible for whole event was An Le, Lang Qianqiu's best friend who betrayed him in the name of his native kingdom, Xian Le. The only one other known conspirator was Qi Rong, Xie Lian's own cousin. (Source: Fandom Wiki)