Ji Hao truly didn't want to spare these disciples of Priest Mu.
Ever since Ji Hao rose among human beings, the higher the position he reached, the greater the power he seized, the heavier the pressure would Priest Hua and Priest Mu lay on him. Obviously, Priest Hua and Priest Mu didn't want to see any disciple of Yu Yu stand at a high position in the human society.
For quite a few times, Ji Hao nearly died at the hands of Priest Hua and Priest Mu's disciples.
The stronger Priest Hua and Priest Mu' disciples were, the more powerful their sect was, the greater pressure Ji Hao would have to take in the future from them. Among the ones trapped by Ji Hao in the heaven and earth great formation, human warriors were all human slaves saved by the four from the mines in Yu Dynasty. They fervently believed in Priest Hua and Priest Mu. After all, it was they who sent people to save them from the dark place where they struggled to live.