C494 Power of four emperors

Grandma Meng didn't answer the crown prince, but told us another thing that we didn't know about. We all know more or less about Mi Ziqi, but what Grandma Meng told us is related to Mi Ziqi.

After the Great War of Gods and Demons, the Emperor of the Underworld and the Demon Emperor used their divine powers to seal the Demon Emperor. However, the Demon Emperor was restless in the Demon World