Starting With The Yin-Yang Holy Body

Ye Chen finds himself transported to a martial world ruled by strength, where righteous sects soar through the skies, demons ravage the land, and ferocious beasts thirst for human blood. In this perilous realm, only the strong determine the fate of others.
Without any talent for cultivation, Ye Chen is assigned as the gravekeeper of the Ziwei Sacred Land’s ancestral temple. Just when all seems hopeless, the Sign-In System activates, allowing him to uncover countless treasures within the sacred grounds.    
For ten years, Ye Chen remains hidden, steadfastly guarding the temple, as chaos brews in the outside world.
When the long-anticipated war between righteousness and evil erupts, and the demonic forces invade Ziwei Sacred Land, their conquest halts before the unassuming gravekeeper.    
Who is Ye Chen, and what power lies hidden behind his humble facade?