Rylon, a male Human, functioned as an Imperial spy working secretly as a Commander within the Galactic Republic throughout the Cold War.
While serving as a spy for Darth Baras in 3643 BBY, Rylon commanded Republic forces in an engagement against the Empire on the planet of Balmorra. Subsequent to seizing control of a Balmorran manufacturing plant, Rylon and his unit were confronted by Baras' apprentice, dispatched to assassinate Rylon due to the risk of his exposure. Following the demise of his entire squad, Rylon found himself face-to-face with the Sith Warrior. Rylon voiced his unwavering dedication to the Empire and readied himself to battle the Sith, but the Sith Warrior ultimately slew Rylon in the ensuing confrontation.
Rylon fathered a son named Durmat, who also met his end at the hands of Baras' apprentice because he possessed knowledge of his father's true allegiance.
Following Rylon's demise, Jedi Knight Mashallon documented the exchange and endeavored to alert the Jedi Council and Jedi Master Nomen Karr about the Sith's pursuit of Nomen's apprentice by transmitting her discoveries. Nevertheless, Lieutenant Malavai Quinn intercepted the communication, resulting in Mashallon's failure to achieve her objective.