The Mysterious Bone Passes Down to the Azure Cloud Realm

This is a spin-off based on an anime about a mortal's journey to immortality.

Venerable Xuan Gu was not completely defeated by Han Li. A wisp of his soul survived, hiding where the original Void Heaven Hall had stood. But the Void Heaven Hall was no mere ruin for adventurers to explore. Millions of years ago, it was the site of a great battle between the Sword Dao Master of the Celestial Realm above the Dome and the strongest Dao Master of the Thirty-Two Heavens of the Immortal Realm in the mortal world, the Hongmeng Dao Master. As expected, Hongmeng emerged victorious. He severed a celestial palace and set up several arrays to extract the Sword Dao Master's consciousness, leaving behind only a lingering ghost, ground down for millions of years. When it later encountered Xuan Gu, its attempt to possess him failed, and Xuan Gu instead made it his soul servant. Meanwhile, Xuan Gu opened a secret passage in the Void Heaven Hall leading to the Qingyun Realm, setting off on a new adventure.