I know I want to make someone that has a lot of trouble, is good in a fight, and not afraid to get his hands dirty. Protectorate, I'm thinking, but more in an infiltration behind the lines type of way instead of CTAC. Not on good terms with his unit, though he doesn't know why. Old enough to have a bit of experience in different conflicts, but still pretty young comparatively.
Rolling up a name, one that catches my eye is London Tian.
Tian was born offworld on the frontier- a backworld planet Gui Xiu VI. He was recruited young, and trained into CTAC. He had an aptitude for getting into places he wasn't supposed to be, and more importantly getting out. In his relatively short life, he's inhabited many sleeves, casting anywhere they needed inside information. He was good at his job, and though he had no real long term aspirations, it was easy to see that his star was on the rise. On a pretty routine mission for the Protectorate, he was debriefed- then he doesn't know what happened. He woke up in a new sleeve on Earth in a re-sleeving facility. 50 years had passed since the last time he was spun up. He was cashiered out of the military, and he doesn't know why. For a re-sleeve, he was given a decent sleeve as his severance, so he was very suspicious of the circumstances. But with no contacts and no way of finding out what happened, he's done the best he could, taking odd jobs putting his skills to use as he tries to amass enough contacts and resources to find out what happened to his career, his life, and his own sleeve.
I had to make up the planet name, as the base rulebook only gives info about Earth. Disappointing, but I figure I can wing it.