The biggest issue the Great Ming Divine Dynasty faces is preserving its interests and avoiding becoming everybody's target in the upcoming return from the innumerable miles of the Sky Wasteland.
Understanding the specific situation in the Sky Wasteland and planning ahead is their current priority.
The most suitable person to provide this understanding would be the mysterious Mr. Wu. However, he stays day and night at the Imperial Astronomical Observatory with Bai Xiaosheng, so he is naturally excluded.
The siblings Xue Hanyi, who have been at Shenxiao Mountain for several years, and their ambiguous relationship with the Shenxiao Sect, are not good choices either.
The most suitable person, on the other hand, would be Mu Binghua from Heart Moon Lake. Although she is close to the Shenxiao Sect, after understanding the style of the forces at Heart Moon Lake in the Sky Wasteland, Gu Ji decisively invited her to discuss matters about the Sky Wasteland.