After Upgrading to Defeat Monsters in the Spirit World, He Became the Supreme King of the Underworld.

Gong Bian was hunted down, and the cat demon Gui Yan escaped from the underworld to the spirit world with the Pluto's Jade Seal. In the spirit world, he got help from the fox demon Tushan Zili. The two became friends and later followed Tushan Zili to study at Wanling University. Now that he has come, he will make peace with it. Gui Yan decided to settle down in the spiritual world now, and wait until he has accumulated enough strength to find the missing Pluto, then open the door to the spiritual and dark worlds, and return to the underworld to regain everything he lost. But while searching for clues about Pluto's whereabouts, a secret about the sky is being quietly revealed. Should he return to the underworld when nothing happens, or should he join hands with his friends in the spiritual world to crush the darkness in the outer world. What happened in the past and where to go in the future, all of this seems to have its own destiny.