Darth Vader was encased in sinister black armor. The man underneath was mortally wounded in a lightsaber duel, and the dark suit includes extensive machinery to keep Vader alive. The sounds of his mechanical lungs accompany his every step. Such injuries greatly diminished his ability to use the Force, but Vader is still very powerful. He can command the power of the dark side to hurl objects or remotely crush the throats of his victims.
At some point, Darth Vader received word that the Jedi Kento Marek had secretly taken refuge on the Wookiee homeworld of Kashyyyk. Investigating this, he launched a full scale invasion on the planet. The initial attack was a disaster, as Vader's 501st Legion found the Wookiees surprisingly well prepared, thus causing Imperial forces to be initially overwhelmed by Wookiee resistance. Vader berated the Imperial commander who was in charge of the operation and nearly Force choked him to death. However, the Sith Lord allowed the officer to live, as he was ultimately unconcerned with the outcome of the battle; the Jedi fugitive was his only concern.
While the 501st fought the main Wookiee force, Vader led a squad of stormtroopers to the Jedi's location. Marching through the Wookiee village where the resistance was centered from, they brutally cut down any Wookiee in their path, crushing the natives without mercy. Eventually, they made their way to a large hut at the center of the village where the Jedi was waiting for them. With no option other than to fight, Kento Marek resorted to confronting the Sith Lord directly, trying unsuccessfully to convince Vader to back down, and then killing Vader's stormtrooper escort with a telekinetic blast. Unharmed from the attack, Vader activated his lightsaber and Kento responded in kind.
Despite a valiant effort, Kento was ultimately no match for Darth Vader. The Sith Lord evaded all the Jedi's telekinetic attacks and simply and easily proved his superior duelist skills in comparison to Kento's simplistic blade-work. Ending the duel with a sudden power blow, Vader disarmed Kento of his lightsaber, shattering the weapon against the ground.
Before the Jedi could recover, Vader seized him through the Force, pummeling him about before hurling him through the front door of the Jedi's hut. Marching inside, Vader confronted the fallen Jedi, again elevating him off of the ground. However, Vader suddenly felt the presence of another Force-sensitive, one far more powerful than the Jedi he had just defeated. Initially believing the presence to be that of Kento's master, Vader demanded to know his location, only for Kento to state that the Sith Lord had already killed his master prior to their battle.
Seeing no further use in Kento's life, Darth Vader declared that the Jedi would share his master's fate. Just as Vader raised his lightsaber to strike Kento down, the weapon was suddenly snatched from his hand by a powerful Force pull. While still holding the Jedi in his grip, Vader swiftly turned around to see who had disarmed him, only to be utterly shocked to see his lightsaber in the hands of a young boy. Realizing that the powerful presence he felt through the Force was emanating from the child, Vader quickly deduced that the Jedi fathered a son, Galen Marek. Kento told his son to flee, but Galen was stricken with too much fear to move from his position. In response, Vader crushed the Jedi's throat and dropped his dead body in front of the young Galen. As Vader cautiously tried to approach the boy, a group of stormtroopers and their Imperial commander entered the hut. Seeing the child with Vader's lightsaber, the commander realized the boy was a Force adept and ordered the troopers to gun him down. However, before they could do so, Vader reclaimed his lightsaber and executed the commander and his stormtroopers present, not wanting anyone other than himself to know of the boy's existence or his extraordinary Force potential.
Darth Vader had saved Galen Marek's life, but only with the intention of turning the boy to the Dark side of the Force. He had sensed the boy's strength in the Force, and was determined to indoctrinate Galen into the ways of the Sith. Having finally found the apprentice he was searching for, Darth Vader departed from Kashyyyk with his new disciple, keeping the boy's existence a deeply guarded secret for years to come.
After losing his father during his childhood, Galen Marek was raised by Darth Vader in secrecy for nearly the rest of his young life. In time, Marek ultimately forgot his past, including his parents and his birth name. To Vader and the few others who knew of his existence, he simply known by his codename Starkiller. Despite forsaking his former persona as "Anakin Skywalker," Darth Vader secretly harbored a great deal of anger towards his Master, Darth Sidious.But due to the injuries he suffered on Mustafar, Vader knew that he was in no position to overthrow Sidious alone. To that end, Vader broke with the Rule of Two, the ancient Sith tradition that permitted only two Sith-trained individuals at a time, by training Starkiller as his Sith apprentice. For roughly two decades, Vader consolidated a virtually unbreakable psychological hold over the apprentice, controlling him first through fear, and then teaching him to embrace his anger and hatred in order to grow in strength through the Dark side of the Force.
However, despite the psychological torment and sheer brutality of his training, which bordered on torture, Starkiller developed a great sense of loyalty towards Vader, essentially because the Sith Lord's callous treatment was all he knew. Throughout his training, he operated as Vader's personal assassin, dispatching treacherous officers and rivals of Vader, all the while eagerly anticipating his eventual confrontation with a Jedi. As he grew older and increasingly immersed in the ways of the dark side, Vader promised his apprentice that when the time was right, they would destroy the Emperor. That promise had become the focus of Starkiller's entire existence, making him eager for the day when he could stand at Vader's side as his "official" apprentice, in accordance with the Rule of Two.
Among the few items that Vader provided Starkiller with was an prototype holodroid companion named PROXY. Although Vader intended for PROXY to be a tool that helped the apprentice to develop and refine his lightsaber skills, the Sith Lord unwittingly provided Starkiller with the only friend he would ever have while growing up, partially undermining his full commitment to the ways of the Sith. In order for the apprentice to track down targets throughout the galaxy, Starkiller was given control of an advanced prototype starship known as the Rogue Shadow, equipped with both a hyperdrive engine and an experimental cloaking device. Although a capable pilot in his own right, Vader preferred that the apprentice focus strictly on his Sith training at all times. Hence, he personally reassigned several Imperial officers to pilot the Rogue Shadow during the apprentice's missions. However, none of the apprentice's seven pilots survived their assignment. Some were killed during Starkiller's more dangerous missions, while others were summarily executed by Vader himself due to some perceived failure.
In 3 BBY, Darth Vader had determined that Starkiller's training was nearly complete. The apprentice had all but completely surrendered to the power of the dark side. By this time, the apprentice had been indoctrinated with unquestioning loyalty to Vader, as well as utter hatred for the Jedi. Vader informed his apprentice that before they could destroy the Emperor, Starkiller had to first prove his reliability by hunting down and slaying multiple Jedi fugitives in a final series of tests. Vader also warned Starkiller to use maximum discretion during his missions, so as to not alert the Emperor to the existence of Vader's secret apprentice, and thus their plot to dethrone him. Hence, Vader instructed the apprentice to kill anyone who saw him during his missions, Imperials or otherwise. Starkiller, having long since desired to test his skills against real Jedi, eagerly obliged his master with great anticipation. After killing the Rogue Shadow's last pilot, however, Vader was forced to choose a new pilot before dispatching the apprentice on his latest assignment. His choice settled on Captain Juno Eclipse, the former commanding officer of his Black Eight Squadron. Although Starkiller did not dare to express his concerns, he suspected that Vader selected Eclipse with the intention of testing his apprentice in some way.
Darth Vader's training proved remarkably effective, enabling Starkiller to annihilate all who stood in his way with lethal efficiency, including some of the last known Jedi in the Galaxy. When he returned from his duel with Rahm Kota in the TIE Fighter Construction Facility above Nar Shaddaa, he presented Kota's lightsaber to the Sith Lord. However, Vader felt that his apprentice lacked focus and still had much to learn before he was ready to fight another Jedi. To that end, Vader dispatched Starkiller to the fallen Jedi Temple on Coruscant for further training. When Starkiller successfully completed the Trial of Skill, Vader provided the apprentice with new orders to travel to Raxus Prime and kill the Jedi fugitive Kazdan Paratus.
Despite Vader's belief in the unlikelihood of his apprentice's survival against Paratus, Starkiller triumphed over the Jedi Master, determined to prove that he was worthy to stand at Vader's side and destroy Emperor Palpatine.
Although Starkiller had proved that even some of the most seasoned Jedi warriors were no match against his raw power, Vader was hardly impressed by victories over an "old man" and an "outcast." He demanded more evidence of Starkiller's strength in the dark side before sending him to confront a more challenging Jedi Master. Thus, he sent Starkiller back to the Jedi Temple to participate in the ancient Trial of Insight.
After Starkiller successfully completed the trial, Vader congratulated his young apprentice and felt that the time was right to finally test Starkiller's abilities against Shaak Ti, a former Jedi General who served in the Clone Wars and one of the last members of the Jedi Council. With great anticipation that this next kill would finally lead him to his "destiny," Starkiller immediately traveled to Felucia, overcoming all that stood in his way on the jungle-infested world and justifying Vader's faith in him by killing the legendary Jedi Master.
With Shaak Ti's death, the last of Starkiller's trials had been completed. Darth Vader recalled his apprentice back to Executor, where Vader assured Starkiller that they would finally kill Emperor Palpatine and rule the galaxy together as Master and Apprentice.
But unknown to Starkiller, the Emperor's spies had been following him since Raxus Prime, tracing him back to Vader's flagship. Vader, faced with certain death for his "betrayal," in turn betrayed his shocked apprentice by impaling him through the chest with his lightsaber. After a moment of pause, Vader threw Starkiller into the vacuum of space by hurling him through the bridge window, at his master's command. However, Vader made sure that Starkiller's body was retrieved and brought to his science vessel, the Empirical. Upon the apprentice's full recovery, Vader excused his betrayal as a necessary course of action, both to save their lives and to fool Palpatine into believing that the secret apprentice was dead. Starkiller, although clearly bitter over the betrayal and denied a chance to finally become a true Sith Lord, nevertheless resigned himself to his fate and obediently submitted once more to his master's will.
With his every move under close observation, Darth Vader charged his apprentice to create a distraction that would divert the Emperor's attention away from him. To that end, Starkiller was ordered to create an alliance of rebels and dissidents so that with the Emperor distracted by a direct threat to his authoritarian rule, Vader and his apprentice would finally be able to assassinate the Emperor while his guard was down. Thus, he ordered the apprentice to take great care in maintaining the secrecy of his mission, so as to not alert the Emperor of his survival, nor reveal his Sith identity to his imminent rebel allies. Before cutting off his transmission through PROXY, Darth Vader left the apprentice with one last reminder—the dark side would always be with Starkiller.
When Starkiller found a valuable ally in Bail Organa, Starkiller was told that he needed a target to show that the Empire was vulnerable to those that silently opposed it. Seeking his master's council, Vader suggested that the Star Destroyer shipyard over Raxus Prime would be a sufficient target as the clearest sign of the Empire's reign through fear was symbolized by the awesome might of the Star Destroyers. Although his apprentice remained loyal, Vader could sense that Starkiller was developing feelings for his supposed allies. He sternly reminded the apprentice of where his allegiance truly belonged, a fact which Starkiller solemnly accepted.
Afterward, Vader informed the apprentice of the extent of his successful mission, claiming that Palpatine was greatly displeased at the events on Raxus Prime. Starkiller advised that he could not maintain communications with Vader for the time being, mainly so that the Rebels would not suspect his identity or his past under Vader, which could potentially undo all that he had accomplished in forming the Rebellion. However, Darth Vader had other plans and swiftly captured the Rebel senators when they met and signed the Corellian Treaty on Corellia. After revealing to the leaders of the seemingly short-lived Alliance to Restore the Republic that Starkiller was the Sith Lord's secret apprentice, Vader once again assaulted his pupil, only this time with true lethal intent. Unable to bear a second betrayal, Starkiller bitterly lamented that he had been played a fool once again, to which Vader informed him that he never intended to destroy the Emperor—at least not with Starkiller at his side. It was then that the apprentice realized the truth—that he was just as expendable as absolutely everything, and was meaningless to Darth Vader. Credits, starships, Imperial lives—they were all meant to further the goals of his master, and by drawing out the Rebel leaders into one place just so they could be revealed and arrested, Starkiller had fulfilled his purpose and outlived his usefulness. Just as he was on the verge of killing his apprentice, PROXY, under the holographic guise of Vader's former master Obi-Wan Kenobi, distracted him in a short duel. Although Vader easily defeated the holodroid, Starkiller was gone, having fallen off the cliff outside the rebel site.
Vader brought the Rebel senators to the Death Star I, where they would be interrogated through torture in order to reveal the location of their friends and allies, only to be publicly executed by the Emperor in order to silence further opposition to Sith domination. To everyone's surprise, Starkiller was still alive and had infiltrated the incomplete battle station with the intention of rescuing the Alliance leaders, as well as to seek revenge against his former master. As a sign of his bitterness toward Vader's repeated betrayals, the apprentice dropped the code name and persona of Starkiller, thus accepting his birth name Galen Marek as his new identity. At the Emperor's order, Vader reluctantly went to confront his former apprentice. As they came face to face, Vader taunted Marek that he still had much to learn. Much to Vader's surprise and frustration, the Sith Lord was utterly caught off guard by Marek's considerable skill and feral-like ferocity. Unable to overcome Marek in close combat, Vader disengaged from his blade-to-blade tactic and retreated to the throne room antechamber, attempting to overwhelm Marek with a relentless telekinetic assault.
However, the sheer weight of Vader's heavy armor and prostheses left him unable to physically compete with the agile Marek. Furthermore, the numerous cybernetic additions to his body considerably diminished his potential in the Force. Ultimately, the apprentice had surpassed the master—the irony being that this was the Sith way, yet Marek was never "officially" a Sith apprentice. With the Force on his side, Marek crushed Vader under a pile of heavy pipes and unleashed a furry of swift attacks that brought Vader to his knees. After pummeling away a few times at the last of Vader's defenses, Marek viciously sliced off the upper part of Vader's mask, then used the Force to brutally fling his former master through a glass pane and into the throne room. Darth Vader, damaged and no longer capable of defending himself, had finally been defeated.
Emperor Palpatine was greatly pleased by the outcome of the duel. Shortly after his reign began, Palpatine gradually became as bitter and spiteful of his apprentice as Vader was with him. He had spent more than engineering Anakin Skywalker's fall to the dark side, only to see his perfect apprentice's Force potential greatly reduced by his near-death injuries on Mustafar. After seeing Vader humbled and beaten by a superior opponent, Palpatine wasted no time in encouraging the young apprentice to kill his weak and broken master, thus finally becoming a true Sith Lord and taking his rightful place at the Emperor's side. After a few moments of hesitation, Marek chose to follow the light side of the Force by confronting the Emperor. Catching him by surprise, Marek quickly overpowered the Emperor. Far from accepting defeat and, much less, death, the Emperor goaded the apprentice one last time to give into the dark side—by slaying the Emperor himself in anger and hatred. With General Kota's help, the apprentice resisted the dark side one last time. Outraged, the Emperor struck Kota with Force lightning, refusing to let the Jedi and Rebels have someone as powerful as Marek on their side. However, Marek thrust himself in the way to protect the Jedi and the former senators.
By this time Vader had recovered enough to muster a squadron of stormtroopers in order to kill the Rebels and his former disciple. As the stormtroopers pursued Kota and the senators, Vader could do nothing more but watch as his master and apprentice locked with each other in a chain of Force lightning. Marek, fully aware that he would not survive against the full fury of the Emperor, sacrificed his life and with one last defiant yell, he caused a massive Force explosion that killed all of the stormtroopers in the room and temporarily incapacitated the Sith Lords long enough for the Rebels to escape. After regaining his senses, a severely injured Darth Vader slowly approached the body of Galen Marek, just as the Emperor also recovered and looked down at Marek's corpse with utter shock and disappointment. Darth Vader, his voice solemn, noted that the secret apprentice was truly dead this time.
Darth Sidious was displeased and frustrated at having suffered such an unusual setback. Not only had he failed to kill the leaders of the newborn Rebel Alliance when he had the chance, he also realized that Marek's selfless act of sacrifice would inspire the Rebels and bolster their morale to the point where silent opposition would be replaced by an all-out rebellion through force of arms. Vader swore that he would hunt down and put an end to this new threat, while also feigning ignorance at his master's betrayal. Having failed to replace Darth Vader with Galen Marek, the Emperor had no choice except to tolerate Vader's existence for a while longer, at least until he could find a new apprentice of the same caliber as Starkiller.
In the aftermath of Galen Marek's death, Darth Vader salvaged the body of his former apprentice and brought it to Kamino, where he stored it in a secret chamber in the Timira City Cloning Facility. With Marek's body serving as a genetic template, the Sith Lord endeavored to create the perfect version of his fallen disciple—a clone that possessed all of Marek's power, but none of his weaknesses.
But due to the initial imperfections in the accelerated cloning process, the first batch resulted in aberrant clones, subjects that were both physically deformed and mentally deranged. Other clones that were not as unstable also ended in failure, mainly due to the memory flashes that were used in their training. Although many clones made it far in their trials, Vader noticed how they were all undermined by at least two common factors—the memories of their progenitor's life and his emotional sentimentality. Ultimately, they were all haunted by visions of a past life that none of them lived, thus leading to cases of identity crises due to their inability to free themselves from Marek's memories.
As Vader's secret project continued to suffer through trial and error, one clone in particular showed a great deal of promise. The clone progressed far in his training, to the point where Vader considered dispatching him to Cato Neimoidia to execute Rahm Kota. Although he was impressed with the clone's progress, he noticed how this version was just as troubled by Marek's memories as all of the other clones had been. In order to see if the clone was truly strong enough to overcome his template's emotions, Vader provided the clone with a challenge to destroy Sith Training Droids that had taken on the holographic appearance of Rebel troopers. Although the clone easily destroyed the troopers, sparing no feelings for the organization that his progenitor helped to create, he was suddenly dumbfounded by the droid that had taken on the image of a woman he recognized as Juno Eclipse. When Vader commanded the clone to strike her down, demanding him to hate that which Marek loved, the clone struggled to obey, but ultimately refused.
His fears confirmed, Vader destroyed the training droid, causing the image of Juno Eclipse to disappear. Disappointed with yet another failure, the Sith Lord revealed to the dumbfounded clone the fact that he had tried many times before to create a perfect version of his original apprentice, only to fail when it came to purging them of the emotional imprints. Despite the successful growth and progress of a different clone of Marek, Vader lied to the clone by telling him that the accelerated cloning process was still imperfect. Before Vader could rectify his mistake by killing his latest failed experiment, however, the clone unleashed a blast of Force lightning at his master after receiving a vision of Vader's first betrayal of the original Starkiller. While Vader was momentarily dazed by the attack, the clone blasted a hole through a wall and jumped outside in order to escape. In response, Vader alerted the cloning facility's Imperial garrison and commanded them to kill the clone; none of the troopers succeeded. With his troops having no success in killing or stalling the clone, Vader moved to intercept him before he could escape, only to see the clone steal his TIE fighter and escape from Kamino. During the clone's travels, he became known by Marek's codename Starkiller after refusing to go by his progenitor's birth name.
Shortly after the clone's escape, Darth Vader contacted Boba Fett, the bounty hunter who's skills made him a reliable asset to the Sith Lord. When Fett arrived on Kamino, he surveyed the damage to Timira City and concluded that it would take some time to discover Starkiller's whereabouts. Knowing that the bounty hunter would never be able to capture Starkiller directly, much less survive an encounter with him, Vader commanded Fett to abduct Juno Eclipse, the former Imperial captain who had joined the Alliance as commanding officer of the Salvation. Since the clone had inherited his template's emotional attachment to Eclipse, Vader anticipated that the clone would never be able to resist returning to Kamino to save Eclipse.
Despite his own talents, Boba Fett knew that he was not capable of single-handedly assaulting a Rebel cruiser and capturing it's captain all on his own. To that end, he requested Vader for enough stormtroopers to aid him in completing his mission, though he lacked confidence in the troopers' ability to survive. Vader's only concern was bringing the clone back to Kamino, regardless of how many resources he had to use to achieve this goal. Thus, Vader provided Fett with far more than what he requested, such as Terror Troopers, Terror Droids, Terror Biodroids, and a Terror Walker.
Around this time, Darth Vader was training another clone that showed a great deal of potential. Unsurprisingly, this clone inherited the same disturbing memories and emotions of his genetic template just like his brothers before him. Upon being released from his cloning tank, the clone was confronted by Marek's memories of Juno Eclipse, thus causing the clone to ask about her whereabouts. Vader simply stated that Eclipse was irrelevant, and all that mattered was the training that lay ahead for the clone.
In the early phase of his training, the clone revealed to Vader that he possessed memories, but could not tell if they actually belonged to him. Having dealt with enough of Marek's clones suffering from an identity crisis, Vader knew all too well what the clone was talking about. He simply explained that the clone was copied from the cells of Marek's corpse, thus allowing him to inherit the original Starkiller's strengths and weaknesses. Although the clone continued to survive in his trials, Vader was not yet fully convinced that this was the one he sought to create, recalling all of the other clones that made it far in their training—only to fail in the end. Even though the clone was determined to not fail his Master, it didn't stop him from becoming curious about the exact number of clones that came before him, or from wondering about what his progenitor was like as a person before he died. Vader dismissed the clone's questions as pointless curiosity. All that mattered to him was if any more clones would be created if this one failed. With Marek dead and his power surpassed by the clone, Vader felt that delving into the details of his original apprentice's identity was irrelevant.
To the amazement of both the lead cloning technician and Darth Vader, the clone was gradually able to compartmentalize his template's memories while forming new ones of his own. Thus, he succeeded in achieving what none of his brothers were capable of doing—holding Marek's memories as separate from his own experience. By doing so, the clone had come to know for certain that he was a copy and that the original Starkiller was truly dead. Vader greatly approved, and promised to prove what the clone already knew to be true. That proof was revealed by Vader to be the body of the late Galen Marek, stored within a cold chamber in Timira City. By seeing Marek's corpse with his own eyes, the clone understood that he had succeeded where all of the clones failed before him, and that he was well on his way to fulfilling the purpose of his creation—much to Vader's delight.
Near the end of his training, the clone had apparently severed the last remnants of the emotional imprints left behind by Galen Marek. After striking down a Sith Training Droid disguised in the holographic image of Juno Eclipse, Vader asked the clone how he felt. The clone replied that the emotions he felt were hate for his template's failings, disgust for his weaknesses, and pride for rising above them. Hence, Vader's goal had finally been accomplished. After a long line of failures, a single successful clone had risen to become his Dark Apprentice. When the Rebel Alliance launched an assault on Kamino's Imperial defenses, Vader ordered the Dark Apprentice to not interfere unless he was needed, and only then would his training finally be completed.
Shortly before the battle, Starkiller, the renegade clone who escaped from Kamino, received a vision of the imminent future. In this vision, he saw how the Dark Apprentice would kill him if he tried to destroy Darth Vader, who had been disarmed and defeated in the vision.
When Boba Fett returned to Timira City with Juno Eclipse as his prisoner, Darth Vader greeted both of them in person. Although he was slightly tempted to summarily execute Eclipse for treason, as well as the inconvenience that the Alliance caused for him, the Sith Lord maintained his focus on using Eclipse as bait to lure Marek's wayward clone back to Kamino. Although Fett wanted to leave the planet before the battle commenced, acknowledging the fact that his limitations would most likely get him killed in a direct confrontation with Starkiller, Vader commanded the bounty hunter to remain planet-side until Starkiller arrived, thus withholding Fett's payment. Accompanied by a squad of stormtroopers, Darth Vader and Juno Eclipse proceeded to a tower located at the top of the cloning facility.
When the battle began, Starkiller directed the Salvation on a collision course with Timira City. While Eclipse and the stormtroopers became increasingly nervous, Vader maintained a calm stance and awaited the clone's return. While the first half of the ship crashed into the cloning facility, Starkiller destroyed the second solid fragment so as to not inadvertently harm Eclipse. While the clone made his way to the top of the facility, killing all Imperials in his way, Vader secured Eclipse in the tower and moved to confront his former apprentice.
Within the cloning facility, Darth Vader and Starkiller engaged in a lightsaber duel. While Starkiller pressed his attack and demanded to know where Eclipse was, Vader stood his ground against the clone. Having learned his lesson after nearly being killed by Marek, Vader did all he could to put a sufficient amount of distance between himself and Marek's clone. Thus, he used his powers several times to throw multiple cloning tanks, but to no avail. In order to stall Starkiller, Vader also unleashed various imperfect clones of Marek and commanded them to attack their renegade brother. Starkiller was shocked to see that there were other clones of Marek besides himself, thus learning how he was wrong in believing that Vader had lied about creating other clones before him.
After defeating the aberrant clones, Starkiller pursued Vader all the way to the cloning tower where he found Juno Eclipse at Vader's mercy. The Sith Lord elevated Eclipse off of the ground and began choking her through the Force. Vader gave the clone a final chance to surrender, or watch as he killed Eclipse. Overwhelmed with fear and concern for Eclipse's life, Starkiller dropped his lightsabers and obeyed, promising to serve the Sith Lord once more as long as Eclipse remained unharmed. Satisfied, Vader released Eclipse from his grip and commanded the clone to kill General Kota. With nothing but silent compliance from the clone, Vader told Starkiller that he would go on to become fully immersed in the dark side and that he would execute the Alliance leaders; resistance of failure to meet any of Vader's expectations would cost Juno Eclipse her life.
However, Eclipse refused to be the catalyst for Starkiller's return to the dark side and attempted to assassinate Darth Vader with one of the clone's lightsabers. Vader narrowly avoided her strike, warned by his senses at the last second, only taking damage to his chest panel from the saber attack. In retaliation, Vader blasted Eclipse out of the tower, causing her to fall on a landing platform before losing consciousness. In a rage, Starkiller grabbed both of his sabers and attacked Vader, only to be thrown out of the tower as well. Before he could get to Eclipse, Vader jumped out of the tower and landed on the platform, purposely standing between the clone and Eclipse. Although Starkiller could not understand why Vader would risk his life by damaging or even destroying the one tool he could use to control him, the clone came to believe that it is what Vader wanted all along. By killing Eclipse, Vader intended to remove Starkiller's only reason for resisting his purpose as a Sith, thus causing Starkiller to fall headlong back into the fold of the dark side.
As the two engaged in combat once more, Vader tried to convince the clone to rise above his concern for Eclipse, stating that her life was meaningless and that her death fueled his strength in the dark side. He reminded the clone that his feelings for the woman were counterfeit, nothing more than the emotional imprints left behind by a man who was no longer even alive. Between trying to kill Vader and get to Eclipse, Starkiller came to suspect that he and his master were more alike than he first believed. He came to wonder how far the Emperor had gone in creating Darth Vader, and how far Vader would go to destroy his master in order to replace him. When he tried to suggest working with the Alliance against the Emperor, Vader continued his attacks with increasing aggression, making it perfectly clear that he wanted nothing to do with the Rebellion.
The battle nearly ended when Vader managed to disarm Starkiller of his lightsabers. But when Vader threw his own lightsaber at Starkiller, the clone caught the weapon and redirected it back at its owner, thus disarming Vader of both his saber and right hand. The duel ended when Starkiller unleashed an overcharged blast of Force lightning at the Sith Lord, the one attack that Vader could not utilize due to the damage it caused to his armor's critical life-support systems. No longer in any condition to defend himself, Vader fell to one knee in submission, only to see Starkiller's lightsaber blade pointed at his throat.
Before Starkiller could decide to kill the Sith Lord, Kota arrived with his squad and urged the clone to spare Vader's life, but only so that the Alliance could take Vader as its prisoner. Starkiller, torn between Kota's reasons and the desire to take revenge, including the vision of what could happen if he did try to strike Vader down, was confused over what to do at first. While Kota implored Starkiller to think of the valuable information that Vader could provide the Alliance with, Vader goaded the clone to embrace his destiny and strike him down. In the end, Starkiller deactivated his sabers and spared Vader's life, thus taking an alternate path from his vision of the battle's outcome, and thus causing the Dark Apprentice to not reveal himself for unknown reasons. Vader was subsequently arrested by Kota and heavily restrained aboard the Rogue Shadow, while Starkiller tended to Eclipse, who had barely survived the Sith Lord's attack on her.
After being secured in a harness that covered most of his body and completely restricted his ability to move, Vader was placed inside the Rogue Shadow's meditation chamber. There, Starkiller visited the captured Sith Lord shortly before the Rebel fleet departed from Kamino. Although he nearly lost his confidence at the sight of his former Master, Starkiller began mocking Vader by gloating on how he chose to spare his life. Although he remained uncertain over his own origins, he dismissed it as irrelevant, stating that he had succeeded in breaking Vader's hold over him. Throughout Starkiller's short display of new-found confidence in himself, Vader remained quiet the entire time and did not indulge the clone with the answers he sought. Seeing the pointlessness in his actions, Starkiller turned to leave.
But at that moment, Vader declared to the clone that he would never be free as long as Juno Eclipse was alive. Refusing to give Vader the satisfaction of seeing the uncertainty in his eyes, Starkiller exited the meditation chamber and left Vader in the darkness of the room where he was confined. After the Rebel fleet left Kamino, Starkiller and Eclipse took control of the Rogue Shadow and departed for Dantooine with Vader onboard as their prisoner—unaware that they were being followed by Slave I, piloted by Boba Fett.
At some point prior to the Battle of Yavin, Darth Vader escaped from captivity and resumed his place at Emperor Palpatine's side. As Supreme Commander of the Imperial Military, he continued to execute his mandate to destroy the Rebel Alliance he unwittingly created through the original Starkiller's actions.