Yuln was a humanoid Sith who was in service to Darth Krayt's Galactic Empire during the time of the Second Imperial Civil War. The year 137 ABY saw Yuln, together with another Sith named Bokar, sent to the planet called Agamar. Their mission was to find any remaining enemy forces following a battle between Sith forces and a combined group of Imperial Knights and Jedi. After the attack on Agamar, three days had passed when Yuln and Bokar met their end, slain at the hands of Imperial Knight Azlyn Rae and Jedi Master Rasi Tuum, respectively.
During the Second Imperial Civil War, Yuln, a humanoid Sith, fought for Darth Krayt, the Dark Lord of the Sith, within his Sith Order. In 137 ABY, Sith–Imperial troops journeyed to the planet Agamar. Their objective was to capture or kill Roan Fel, the exiled Emperor. After the conflict, Yuln and Bokar, a fellow Sith, were dispatched to the surface of Agamar. Their task was to locate Fel and eliminate any Imperial Knights and Jedi allies who had survived.
As the two Sith were searching for survivors three days following the Agamar assault, Yuln informed Bokar that all remaining Jedi and Imperial Knights had perished. A debate ensued between the two Sith regarding the relative strength of the Sith, Jedi, and Imperial Knights who had died in the battle. Their discussion was cut short by Rasi Tuum, a Jedi Master, who struck down Bokar. Simultaneously, Yuln was impaled and killed by Azlyn Rae's lightsaber, an Imperial Knight.
Sith tattoos in red and black covered Yuln's body. He also had three piercings above a scar that ran from the corner of his mouth. Yuln's hair was black. When Bokar took the deaths of numerous Jedi and Imperial Knights on Agamar as proof of Sith superiority, Yuln countered by pointing out that Sith had also died.
The Sith was equipped with a double-bladed lightsaber and wore gray armor.
John Ostrander, the writer, and Jan Duursema, the penciller, brought Yuln into existence in the first issue of the Star Wars: Legacy comic series' Extremes story arc. Dark Horse Comics released this issue on May 26, 2010.