The Gui Feng Xi Zhuang is not anymore an available choice in chinese imperial service, neither in infinity army for PC nor in the mobile version. This since a couple of days. Is it a bug or a new rule?
He’s been banned from ITS for an indefinite period (but allegedly not very long) as a result of the Backd00r event. Apparently if you turn off ITS validation he can be selected in a non ITS list.
Incindentally, this is the Spanish subforum, and this should be in the Army Bugs section ;) @V @Zoe marking this up, since there seems to be a bug. Reasons: I can add Kusanagi to a list without problems, but I can't even open Xi Zuang's profile, selecting his icon leaves it with the last profile selected. There is no such option, the Army only informs you if the list is or not valid, both in the courtesy list and your private one.