Oliver R. Jewelson -- 'Live -- was a starving thief, living off of the meager coin he got by fencing the goods he stole from the houses he broke into. A one-time mugger with a penchant for knocking out decent folk and taking whatever they had on them, he got lucky and took a small crystal shard from a corpulent nobleman. He noticed rapidly that when he held the shard just so, he could walk up behind just about anyone and K.O. them without drawing any attention. 

He rapidly evolved from mugging to burglary, figuring sneaking in and taking the good stuff was easier than risking accidentally clubbing some tough guy and getting his face beat in. Unfortunately, 'Live tried to shoot the moon and steal directly from the Royal Family. They had defenses his talents couldn't penetrate, and he woke up to find himself without the shard and with a long stay at the dungeon.

Then, suddenly, he received an unusual pardon: a commission. Go with these couple of other locals, and help them find more of the shards. He would be given his shard back -- it seemed that no one else could use it with quite the proficiency that 'Live did -- but all of his traveling companions would be acutely aware of his history and have strict instructions to take him out (and take his shard) if he got out of hand. 

He's not stupid -- he knows that, at the absolute minimum, if they get their country's gem back together, the economy will improve. Even if he ends up back on the street, he'll have better targets for his skills. His dedication to the quest might not be as focused has the others', and he is easily distracted by targets of opportunity, but he is determined to see his country restored to its former glory.