Mo Fan's victory over Yu Ang came at a cost - the reveal of his lightning element. However, he is granted seven days to train in the legendary Underground Holy Spring, where it's said to greatly enhance one's power.

But just as Mo Fan begins his training, a mysterious invasion of fierce monsters puts the entire city of Bo in peril. The border defenses are proven useless, and an emergency is declared. Mo Fan's mission becomes delivering the condensed Underground Holy Spring to a secure refuge zone, away from the chaos in the city.

The journey is treacherous, with bloodthirsty beasts and the menacing Black Order standing in his way. Mo Fan must protect the sacred spring from falling into the wrong hands, despite the long and dangerous path ahead.