Subject 13

Subject 13 was a male Rakata born during the time of the Infinite Empire. His name came from the fact that twelve subjects preceded him that were all failures with thirteen being considered a success. This Rakata was noted for being strong in the Force which led to his imprisonment within a Mind prison which was stored on the prison world of Belsavis where he remained trapped for centuries. His essence was strong enough to be infused in the mind prison and prevented him from even killing himself which ensured his entrapment.

During the Cold War, the reconstituted Sith Empire besieged the Galactic Republic prison at the Tomb. In this time, Sith Lord Mohgren learned of Subject and charged Imperials with the task of probing the unexplored regions for the Rakatan mind prison and freeing Subject 13 with the intention of bending him to the will of the Empire. This Imperial entered into the mind prison where Subject 13 intended to move his mind into their body in order to be free from his imprisonment. He was subdued and weakened, however immediately after that Mohgren's apprentice Suvaar entered the Mind Prison and, obeying his master's orders, willingly let Subject 13 take over his body and enter the physical world once again.

Text and facts from the “Subject 13” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.