Star Wars - A Wretched Hive
Bodyguard/Force Sensitive Exile
Doc was a youngling at the time of Order 66. He escaped the massacre and lived life on the outer rim with a good-hearted swoop-bike gang called the Wild Rancors. When the gang leader retired a more bloodthirsty man took the helm and Doc decided it was a good time to explore the galaxy. Being security on a transport sounds like a good way to do that.