At the Critical Point, I Became the Judge of the Ghost Rider in the Underworld and Upgraded.

One of the resentful ghost judges who accidentally traveled to a small place and needs to accumulate merit from the underworld to upgrade. Because the soul-transferring weapon was destroyed, the evil spirits began to do evil in the underworld. The good ghost had no choice but to ask the resentful ghost to cooperate. No one would agree, but only the male protagonist who came from time-travel agreed to this request. Their plan is for the male protagonist to hide his ghost aura and become a low-level evil ghost, but his strength will also change as a result. He can only start training at a low price. It is so powerful that the evil spirits are convinced and dare not do evil until the spirit-transferring weapon reappears in the underworld and completely transforms them. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.