From Pu Mao's words, Ning Cheng learned that there were many entrances to the Eternal Gazing Door, and the one he used was just one of them.
Not long ago, after Fei Si had snatched the ring of the Dao Emperor, he too feared that someone would follow him and escaped immediately. Pu Mao was aware of this because he was nearby. Moreover, he had a longstanding feud with Fei Si; to be able to obtain Divine Crystals and have someone else teach Fei Si a lesson was naturally the best situation for Pu Mao.
However, there was one thing Pu Mao didn't tell Ning Cheng, which was that Fei Si was not alone, but part of a small group.
Ning Cheng also sighed in his heart, indeed where there were people, there was bound to be strife. In other places, why would a Primordial Stage Emperor stoop to do such distasteful acts?
