'She sent us.'
Such a short phrase to change Lai Mingjie's mind. Ever since Xu Rouguang was taken away from him, he had been paying a lot of attention to luck and miracles. If they weren't compensations, they were favors to curry. Emodao was not one to care much about these, but if it was for Xu Rouguang's safety, then he didn't care even if he would grovel on mud. He would always fail to protect everyone close to him... and he wouldn't know what to do if he lost Xu Rouguang in the same way.
As for how he knew it was Nuwa, it was easy. Mao Jixue wouldn't hide her identity from Emodao, and she had no reason to send down her siblings to him. Since Mao Lina seemed to be different from everyone else, only Nuwa could 'command' her. Moreover, Mao Lina was just four; even Mao Jixue would have a bottom line when it came to picking minions.