Turns Out I'm the Demonic Patriarch?

Master Lucian Vance faces death as his Lifespan runs out. Nearing the fated hour, he is attacked at the Sect Gates by the self-proclaimed righteous Eight Sacred Domains. In the nick of time, a transmigrator sharing his name possesses his body. Armed with The System, he begins a grueling quest to punish evil and uphold justice. By completing quests from The System, Lucian Vance earns points to restore his Lifespan. Leading his six disciples, he reclaims their stolen heritage and uncovers the dark secrets of The Eight Domains. Before his peak power and righteous soul, all conspiracies shatter into the light of dawn.