Sarn Ko was a Human male who worked as a freelance assassin during the Cold War between the Galactic Republic and the resurgent Sith Empire. After doing sensitive work for the Empire, he was deemed as "knowing too much" and was send to the Shadow Town prison on Nar Shaddaa. His resistance to drugs allowed him to escape before a bomb was installed in his skull and he desired revenge. He later asked a Galactic Republic citizen to shut down the Empire's prison complex in Shadow Town by destroying the labs and equipment used to install bombs in people's heads.