Founding the Underworld and attempting the law of coexistence for humans, ghosts, and immortals—if the master of reincarnation is a disciple of the Dao Sovereign, it all makes sense. From the very beginning, the Dao Sovereign shouldered the heavy responsibility of protecting the mortal realm and evolving the Heavenly Dao. Aside from the Celestial Venerable, no one cares more about the destiny of the mortal realm than he does.
The Heavenly Dao of the mortal realm is tied to the Dao Sovereign; calling him the ancestor of the Dao is no exaggeration.
As a disciple of the Dao Sovereign, it was the master of reincarnation's duty to protect the upper realm and guard the reincarnation passage. Only a genius deeply versed in the laws of the Dao could attempt to make the three major laws of humans, ghosts, and immortals coexist. This feat was permitted by the Heavenly Dao of the upper realm and granted amnesty by the Heavenly Court of the immortal realm.
Chapter 1983