Among the Lin Family's concubines, there are non-human entities, which Chen Fei has been aware of for some time. A member of the Lin Family once revealed to him that one of the concubines seems to be the divine breed "Sagali."
So the intelligence from the Command Center is not without basis, but its accuracy is still debatable. After all, if there was a real intention to defect, there wouldn't have been a necessity over three decades ago to create the miraculous alchemical artifact "Halo," sealing off the space rift to Cangqiong Star and simultaneously establishing the stellar link "Dimensional Gate" between Cangqiong Star and Blue Star.
Blue Star Humans aren't completely unaware of the "Sagali" civilization, but their knowledge is still limited due to the lack of advanced interstellar transportation means. Currently, the ability to connect Cangqiong Star with Emerald Star via the "Dimensional Gate" is the most they can achieve.
