Yuun was a male breathing Gand who served the Galactic Republic as a technical engineer during the Cold War with the reconstituted Sith Empire. Like many of his species, he referred to himself simply as Gand when he was ashamed. Recruited into Havoc Squad on Hoth at the beginning of the Galactic War, Sergeant Yuun served in the unit until his commanding officer disappeared in 3636 BBY; Yuun spent a year unsuccessfully searching the Unknown Regions for his commander before he left the Republic Military and began studying the technology of the Eternal Empire.
A Force-sensitive Gand from his species' homeworld, Yuun was trained as a Findsman by the shamanistic order. A technical wizard, Yuun abandoned his homeworld in what he considered a logical decision to join the Republic Army during the Cold War which followed the Great Galactic War. Training with the Galactic Republic, Yuun used his Findsman techniques to locate portents to rise through the ranks with a list of great accomplishes. As effective as Yuun's methods were, they were rarely met with understanding or approval from his fellow soldiers. But despite his eccentricities, Yuun's fighting skill and calm approach to any challenge generally earned at least the grudging respect of the men and women he served with.
Yuun during the Battle of the Gauntlet
Stationed on Hoth as a member of Havoc Squad thanks to an appointment by General Elin Garza, Yuun was assigned to take down the Imperial superweapon Gauntlet. Reassembling an Imperial device called the umbra encrypter to crack Imperial codes, Yuun was able to prove his worth to his colleagues and was welcomed to the squad.
When Havoc Squad's commanding officer went missing during the Eternal Empire's invasion, Havoc searched for their leader for a year before being disbanded, with Tanno Vik returning to a life of crime, Forex being called to serve in the Press Corps, and Elara Dorne being removed from Havoc by Chancellor Saresh. Yuun ultimately left the military and traveled to Zakuul to try and understand Zakuulan technology. By 3631 BBY, Yuun was approached by the Outlander, acting on the advice of Juvard Illip Oggurobb for recruitment into the Alliance opposing the Eternal Empire. Yuun was in the process of reassembling a device that would cloak the Alliance base on Odessen from the Eternal Empire's long-ranged sensors. He had already gathered the first seventeen pieces and requested the Outlander's help to recover the remaining three. The Outlander completed this task and the two left Zakuul for Odessen. Upon arriving, Yuun used his intuition to help Oggurobb locate a he lost months ago before pointing out a solution to a thruster heat dissipation problem the Hutt scientist couldn't figure out for a month.
In the Imperial storyline, Yuun leaves the Alliance after Jedi Under Siege because of the Alliance's perceived newfound alignment with the reconstituted Sith Empire and asked that this not be a cause for sorrow for the Commander. However, he left the possibility open to working with the Commander in the future should their paths converge once again.
- Star Wars: The Old Republic Encyclopedia