Feng shen bang

During the reign of King Zhou, an official enters his bedchamber, and is devoured by the monstrous tails of Daji, his concubine. Outside their city, several warriors within a metal wagon discuss their strategies to free the Invisible People and their Chief, when Jiang Ziya appears to them. He tells them that when King Zhou was younger, he let himself become possessed by the Black Dragon for his quest for power.