There is a kind of spiritual bead in this world called Liuli.
For thousands of years, in order to prevent evil spirits from finding the glass beads, Shen Yueshan broke them into pieces and scattered them in the world.
The original body of Liuli Zhu has been reincarnated for thousands of years and is now Cheng Sheng.
Since birth, Cheng Sheng has been able to see ghosts.