Battle of Vjun The Battle of Vjun was an operation carried out by the New Republic against the Imperial Remnant during the Galactic Civil War . Prelude . At the Battle of Endor , both Emperor Palpatine and Darth Vader were killed seemingly ending the threat posed by the Sith . This allowed the Rebel Alliance to take its first steps into becoming the New Republic . However , one of the many members of the Galactic Empire to had survived the Death Star II ' s destruction on Endor was the former clone trooper of the Galactic Republic known as X1 . With the Emperor dead , he sought to form a new Galactic Empire with himself on the throne and declared himself a Sith Lord . Despite his intentions , X1 lacked the necessary knowledge of the dark side of the Force and thus sought to find knowledge to support him in this endeavor . To that end , he took Imperial forces loyal to him to the planet Vjun in order to reach Bast Castle ; a stronghold of Darth Vader ' s and a possible location for many secrets in the dark arts . Learning that his brother had survived the battle , his clone twin X2 decided to stop him and journeyed alongside Jedi Master Luke Skywalker to Vjun . They had received intelligence data that suggested X1 had formed his new headquarters at Darth Vader ' s castle and was being defended by his Imperial forces . The Battle . After entering the Vjun system , X2 worked to eliminate the security satellites around the planet in order to prevent Imperial forces from being aware of the enemy presence in the region . Receiving his orders from the Jedi Luke Skywalker , X2 later boarded the orbiting Imperial Star Destroyer which was unaware of the Republic presence . Once he boarded the ship , the former clone trooper battled stormtroopers in order to access the ships database and learn more about what forces were present on the surface of Vjun . Upon slicing the computer terminals , he received the necessary data and later departed the capital ship and headed to the surface of Vjun . Skywalker later informed that the intelligence he had taken from the Imperial warship indicated that X1 had already left the planet , but also indicated that there was a Sith holocron present on Vjun which needed to be retrieved from inside Bast Castle . However , the Imperial forces were now fully prepared and had TIE / LN starfighter s scrambled to protect the installation from harm . Furthermore , stormtroopers were garrisoned as well as mobilized to combat intruders . This necessitated in X2 using his X - wing to first eliminate the enemy fighters and later land at the hangar where he engaged in combat against the defending stormtroopers . While battling Imperial forces , X2 was informed by Skywalker that the data on the Star Destroyer showed that X1 had taken his genetic father Falon Grey ' s lightsaber and had placed it in Darth Vader ' s trophy room . Fighting through hordes of Imperial soldiers , X2 managed to enter the trophy room and reclaimed his genetic father ' s lightsaber that was lost at Dantooine . He later went to find and retrieve the Sith holocron and just as he entered the inner sanctum , X2 was confronted by security droids left behind by Darth Vader . Fighting of his assailants , X2 was successful in destroying them and later discovered the existence of the holocron within the meditation chamber located deep inside Bast Castle . Upon retrieving it , he was attacked by more Imperial troopers and security droids which forced him to make his way back to the hangar to escape and return to Republic forces . The retrieval of the holocron allowed Luke Skywalker and Republic engineers to decode it in order to find out what X1 ' s objectives were as well as his next destination .