Background
Tono was like many Twileks, born in slavery. His mother passed when he was 4, and he was quickly implemented into the lesser duties in the household of a lesser crime lord. He never even knew who specifically he was working for when he ran away at the age of 12. However he was quickly found and brought back to the household.
After a beating, he was brought before one of the lower leaders. They put him to work scamming the locals. He wasn't good at first, but some lessons (and beatings to keep him focused) made him a quick learner. He developed an eye for detail, and soon became one of their biggest earners.
One day, when he was returning to turn in his earnings, he found the guards missing, the main entrance empty. As he made his way through the building, he found 3 blasters suddenly trained on him. Once the Rebels confirmed he was unarmed, and not a threat, he found out that this small outfit thought they could swindle the rebel alliance. Having never been alone and failing at previous attempts to be alone, the sudden thought of being alone terrified him. So he begged them to take him with them. They finally agreed to, dropped him with a Rebel recruiter who recognized his talents and sent him off for further training.
This felt the same to him. He was doing a job, taking from others and delivering to his bosses.
His third mission changed everything. Gathering intel, he saw a youth being beat within an inch of his life. Memories took over, and he identified with the pain, the terror, and the fear. He used his talents at misdirection to lead the guards to engage with local security, which brought Imperial "peace keepers" down upon the den of smugglers and slavers. No one survived the Imperial intervention. The criminals were corrupt. The Imperials didn't care. The Rebels may have been too late, but they were trying. They were the only ones who were. And at that moment, he became one of them.
Motivation
Peace
No connections