[Coldsaturn]

Yeah. This is the dead end branch that MC will end up erasing, so it went differently from current timeline Xav. That Xav came back after MC was crowned, then disappeared somewhere and finally came back once she was already dead and ascended the throne in her stead. This Xav we know and love instead never came back after leaving with Traceback II.

Both in this myth timeline and the one we ended up seeing as the first myth call Xav a rebel/traitor because he's seeing MC again. In the original myth (the one he ends up living as the Xav that will reach Earth) he would be considered a traitor by the other Backtrackers because he was meeting Queen MC alone. In this myth with the alternative branching future, he would be considered a rebel in general because he's seeing Queen MC without an officially scheduled appointment. It could be a way of echoing both myths and point how his decision to stay close to her wouldn't be seen favorably either way.
I still can't see enough links to the fact that he was at the head of the rebel army that stormed the castle.

Lots of background info on how difficult her reign was though!