The youngest of four brothers, Arkat Galyian was raised military. Well, he was when his father was at home. When his father was off doing military stuff? Yeah, the boy was raised 'Performing arts.' …That doesn't really have the same ring to it, but it was nonetheless effective. Following in his father's footsteps (as did two of his brothers,) Arkat joined the CMC, and rocketed through boot like a whippet on fire, landing on the other side with a pretty cushy position on the Colonial Frigate 'Charon'
Not much happened. Clean record of service, a small medal thanks to getting shot in a little dispute on a hijacked cargo vessel and a few promotions were the defining points of his 6 year career.
Then he received the one letter he didn't want to. Notification of a gas explosion on Picon, destroying the family homestead and killing his parents in the process. Arkat was given leave by his CO, and the brothers rejoined for the last time to watch their parents scatter to the wind. That was the last time Arkat Galyian set foot on a planet.
Less than a month later, the Sergeant was involved in a hostage situation, deemed important enough for the Marine contingent of the CF Charon to intercede. There was a plan, and a good chance of everything turning out well.
Arkat's head wasn't in the game. Still reeling from the loss, he made two mistakes. Big ones. A lot of people died. 34 in total, with 13 being civilian hostages.
It was put down as a permanent black mark on Galyian's record, and his military career has been unsuprisingly stagnant since then. A transfer to the BS Cerberus is put on the table. Crew needed shipping. The Cerberus needed recruits. The commander of the Charon needed to show Galyian that he was still a good marine, without having to go against the obvious mark on his otherwise impeccable record.
And so it was done. Galyian was freed of the ship that carried his mark, and the Cerberus got a career-marine of 11 years.