Sound good - just take alternative identity and you've got yourself another name and history.
Or, don't worry about the cover story as much.
Just make him a former RAF trooper caught outside the wall - but load him up with some serious sneaky skills.
His RAF service is his cover - to most people he's just Captain drake, formerly of the Wei Standing guard who went merc after his world got overrun by the Cappies and the wall came crushing down.
But in reality - that's just the public side of a RAF Intel officer inserted into the military.
Maybe RAF intelligence have forgotten about him when they pulled the wall up around Prefecture X. Maybe they don't care that they left loads of deep cover agents out in the cold.
Or maybe Drake is still getting feed orders from time to time?
