Shrouded Offensive The Shrouded Offensive was an event that took place during the Western Reaches Operation of the Reconquest of the Rim early in the Galactic Empire ' s history . The Empire managed to discover a Separatist enclave , led by General Atticus Farstar , on the planet Ostor , located at the fringes of the Outer Rim , and was important enough for the Emperor ' s enforcer , Darth Vader to be dispatched to the planet to bring it under Imperial rule . The battle was considered to be largely a disaster for the Galactic Empire , the biggest military disaster for the Imperials at the time , for three main reasons : The first , Darth Vader ended up staying behind for the first day of battle , the second was that he , either due to haste or overconfidence , did not deal with reconnaissance beforehand , and the third had Vader assigning General Rohn with direct command over the operation , who was largely an armchair general giving commands from an armored transport far away from enemy lines . According to the clone stormtrooper Hock Malsuum , a veteran of the battle , Hock ' s participation in the event was largely one of the reasons why the battlefield operation turned out decently the first day . As a direct result of the disastrous nature of the operation , Emperor Palpatine had Vader and Hock brought before him for questioning about the results of the mission . Vader also had Hock " lie through his teeth " to the Emperor , which was also the first time Hock met his liege in person . Vader and Malsuum then led a new assault , but the clone commander was shot down . He was able to sabotage the enemy ' s shield , allowing Vader to lead the army in . The army then wiped out all resistance in the city and left it broken . Prelude . In the aftermath of the Clone Wars , several surviving members of the then - defunct Confederacy of Independent Systems , also known as the Separatists , went into hiding on the fringes of the Outer Rim Territories . One of these cells went into hiding at the planet Ostor . They had hidden themselves there under the belief that the newly - formed Galactic Empire ( which had formerly been the Galactic Republic ) wouldn ' t trace them to the planet . Unfortunately for them , the Galactic Empire ' s leader , Emperor Palpatine , had managed to trace them to the desolate planet , and ordered for various Imperial forces to conquer the planet and wipe out the Separatist Holdout . Because of the vital importance to the Empire the operation presented , Palpatine also assigned his top enforcer of the Empire , the Sith Lord Darth Vader to oversee the military operation at Ostor . Vader , however , failed to do proper reconnaissance prior to invading the planet , and did not directly participate in the operation . He instead stayed on - board a " Venator " - class Star Destroyer , and assigned direct command to a general by the name of Rohn . The operation ran into a slight delay due to sandstorms that were plaguing the planet , but it eventually subsided , with Rohn reporting it to Vader . The operation . Phase one . The invasion began with an AT - TE , five AT - RTs , and 246 stormtroopers ( led by the Clone Wars veteran CT - 5539 , renamed " Hock Malsuum . " ) to the Cliffside . Rohn , after reporting to Vader , then ordered for all of the soldiers to take no prisoners , while he himself was in an armored transport far behind enemy lines . The two armies squared - off at a cliffside . The Separatists held a banner which read in part " General Rohn is a " . The Imperial general ordered his forces to advance and take the banner down . Taking casualties , the Separatists slowly fell back . Malsuum noticed something strange about the retreat , and tried to get Rohn to call off the pursuit . He ran to the transport , and Rohn ordered him to stand down . He then boarded the transport , avoiding getting hit by two of the AT - RTs which had been ordered to take him into custody , one of which hit the transport , and Malsuum killed him as the general tried to forbid anyone from retreating . Malsuum was unable to stop the advance , and all the stormtroopers were killed within fifteen minutes by an ambush by Farstar , who had planted two armies on either side of the canyon . Lima Starcourt , Phootla Veer , and Reebo Keen helped plan the defense of their planet . Shortly after the ambush , Vader contacted the transport General Rohn was in and demanded answers regarding the failure . However , Malsuum explained that he ' ll " get the answers from [ Malsuum ] " , explaining that he killed the general earlier . As a direct result of the operation ' s initial disastrous results , both Vader and Hock Malsuum were ordered to report directly to Palpatine for questioning regarding the reason behind the failure . Accompanying the Emperor at that time was Imperial Intelligence Director Armand Isard , Grand Moff Wilhuff Tarkin , and Imperial Advisor Janus Greejatus . Hock ended up " lying through [ Hock ' s ] teeth " to the Emperor during his first meeting with his liege , blaming the loss on Rohn ' s failures . Palpatine told Vader that he expected a more hands - on approach . Afterward , Vader invited him to fly on his wing . Phase two . After Palpatine ordered Vader to take a more hands - on approach , he returned with an " Imperial " - class Star Destroyer . He led Green Squadron in an offensive against the enemy ' s shielded city . They encountered minimal anti - aircraft fire . As they attacked the shield , they were ambushed by V - 19 Torrent starfighters — piloted by followers of the rogue clone Kaddak — and took multiple casualties . They engaged in a dogfight , before the enemy fighters suddenly vanished . Vader and Malsuum realized that they had left their warship unguarded , and the Sith Lord took most of the squadron with him to defend it . Malsuum was then shot down by Kaddak . He woke up in an enemy hospital an indeterminate time later but walked out and found the enemy leaders , who told them that they were fighting to establish their own society . Malsuum then went to sabotage their operation in order to quickly end the fighting . He was able to disengage the shield , allowing the Imperial fighters to attack the city . Vader then led the ground forces into the city . Kaddak personally engaged Malsuum in personal combat . The assembled separatists cheered them on . Malsuum slew Kaddak and then rejoined the assault . The army slaughtered all resistance in an hour as the city was left in ruins from the aerial strikes . Vader proceeded into the city and executed the three leaders , who never drew their weapons . Malsuum and Vader then found the hospital ; the clone trooper called for them to kneel in front of Lord Vader , but the wounded stood defiantly . Vader executed them , although Malsuum called for him to stop . Malsuum then walked away after Vader paused for a moment . Aftermath . The operation turned out to be one of the worst military disasters the Empire had experienced , as well as the worst military disaster at the time . Hock later reflected that his presence was probably the only reason why the operation didn ' t turn out even worse than it had , and noted Vader ' s three mistakes as being the cause of the disaster . He also reflected that the Separatists ' general , Atticus Farstar , was more deserving of his respect than his own commanding officer during the operation , Rohn . What Malsuum saw Vader do during the battle haunted him years later , and he hoped that the cyborg had no humanity left in him . The clone trooper went into a life of agriculture after the offensive . Behind the scenes . The Shrouded Offensive appears in the 2013 comic " " .