If you want to go back in time, it must be more exhausting than when you used the divine grace on the earth. Just like before, Ning Haotian used the power of blood to melt the inscription in the Damotian Star Prison, making the underworld and the yang world merge into one, so he died.

Ning Qi later also tried to save Ning Haotian's life with divine grace, but failed.

"Even if I can't revive them with my current cultivation, as long as I take the ninth step..."