Does the players discover that Han Xiao is one of them (somehow) later, or at least anyone will come with a theory to say he’s aware of the game world and true reality?
Spoiler: You don't want to know this The players never knew or even came up with a conspiracy theory. They simply thought that he has been a really good leader who cared for old relationships especially the ones who have been with him from the very beginning. Spoiler: Ending Although, the ending pretty much gives your question closure. Han Xiao brings the "Galaxy" world to the same reality as the players'. The game suddenly goes inaccessible, and to the players' surprise, he appears on Earth along with the starship fleets of the Black Star Army.
thx! Btw, why players only purchase from Han Xiao and not from each other? In relation to skills, maybe the game world doesn’t allow one to teach another, but the players should be able to purchase a blueprint and share between themselves, no?