Skirmish on Alaris Prime A skirmish took place in 1002 BBY during the New Sith Wars . In that year , Sergeant Dessel of the Gloom Walkers , a unit in the Sith Brotherhood of Darkness , was arrested by Lieutenant Ulabore for mutiny during the Battle of Phaseera , despite the fact that Dessel had gone on to lead the Sith forces to victory . As a result , the troopers of the Gloom Walkers felt dissent toward Ulabore . Shortly after , while on patrol on Alaris Prime , the unit was ambushed by Republic forces . Casualties were heavy on both sides , but the Republic troops were soon forced to retreat . Over the course of the battle , Ulabore was shot and killed by Lucia , a trooper in his unit . Afterward , the other members of the Gloom Walkers kept her betrayal a secret . Prelude . In 1002 BBY , during the New Sith Wars , the Sith Brotherhood of Darkness fought against the Army of Light on the planet Phaseera . As the battle began , the Gloom Walkers , an elite unit in the Brotherhood of Darkness , were ordered by their Sith commanders to attempt to take out a Republic outpost in daytime . Knowing that it would be a suicide mission , the Gloom Walkers objected ; however , their commander , Lieutenant Ulabore , refused to reconsider their orders . As such , Sergeant Dessel knocked Ulabore unconscious and took command of the unit , leading the Gloom Walkers to attack the outpost during the night . They defeated the Republic forces , and Dessel ' s heroics throughout the battle led him to become very popular with the Gloom Walkers ; however , Ulabore was furious and had him arrested for insubordination . Several of the troopers in the unit assumed that Dessel was then court - martialed and killed . The Gloom Walkers thus began to resent Ulabore for his actions , as they believed that Dessel had saved their lives and should have been hailed as a hero . The skirmish . A month later , the Gloom Walkers traveled to Alaris Prime , a moon of the planet Alaris in the Kashyyyk system . They took up patrol on the moon , where they stumbled into an ambush set up by Republic forces — a mistake that one of the troopers , Lucia , knew would not have happened had Dessel still been with them . In the ensuing skirmish , the close - quarters fighting was intense and casualties were heavy on both sides . Lucia hadn ' t forgiven the Gloom Walkers ' commander for ridding the unit of their most talented officer , and during the battle she shot Ulabore in the back from point - blank range , killing him . The skirmish lasted for just a few minutes , after which the Republic troops were forced to break ranks and flee . Aftermath . The other surviving troopers of the Gloom Walkers quietly approved of Lucia ' s actions ; they never reported her betrayal , and Ulabore was registered as having been killed in action . Twenty - two years later , Lucia — who had become a bodyguard of Princess Serra of Doan — hired an assassin , the Huntress , to assassinate Gelba , a leader of the Doan mining caste , after the miners killed Serra ' s husband , Prince Gerran . Lucia compared the occurrence to her actions on Alaris Prime : Serra ' s husband had been killed and Gelba was responsible , so she killed Gelba , just as Dessel had been killed and Ulabore was responsible , so she had killed Ulabore . However , Lucia soon after discovered that Dessel had not actually been court - martialed and executed ; rather , he had survived and become Darth Bane , a Dark Lord of the Sith . Behind the scenes . This skirmish was first mentioned in " " , the third novel of the " Darth Bane " trilogy , written by Drew Karpyshyn and released December 8 , 2009 .