What is the Underworld?
The spirits of the dead originally had no physical form, let alone spiritual awareness. They were created by Houtu, the ancestor of the Underworld clan, after he came to the Underworld. He brought bustle and life to the Underworld, creating millions upon millions of Underworld beings.
Tracing back to the root, Houtu was originally a minor, undistinguished immortal in the Immortal Realm who had been sent to the Underworld to do odd jobs. At first, the Underworld was not yet one of the Three Realms; back then, neither the Mortal Realm nor the Immortal Realm had demons, nor were there so many ghosts and spirits of extraordinary power.
Chapter 1599