Dark Reaper The Dark Reaper was a Sith superweapon created during the Great Hyperspace War ( 5000 BBY ) . Description . The Dark Reaper worked by harvesting the Force using the Force Harvester , a device that killed anything within range by draining its Force energy and focusing it into beams that dealt massive damage to any object . However , the Reaper could not harvest a wound in the Force . The Reaper was also equipped with dark side - powered turbolasers . In order to defeat the Dark Reaper , an ancient Jedi Knight named Ulic Qel - Droma taught the Jedi how to withstand the Dark Reaper ' s effects . History . Great Sith War . A weapon of mass destruction , it was created by the Sith during the Great Hyperspace War and used against the Galactic Republic . During the Great Sith War , Exar Kun rediscovered it doing excavations on Yavin 4 . As it needed massive amounts of energy to function , the Krath had it target the Living Force to provide power . When fallen Jedi Ulic Qel - Droma returned from the Krath he told the Jedi how to defeat the Reaper . The final battle was fought on the world of Thule , deep within the territory of the old Sith Empire . In a calculated strike , a Jedi task force staged an attack on the Dark Reaper and using Ulic ' s information , were able to disable the weapon . Breaking the deadly device apart , the Republic made great effort to hide the pieces on a myriad of different planets . They then hid the power source of the Dark Reaper , the Force Harvester , on the junkyard world of Raxus Prime . During the Great Galactic War , the Sith Emperor and Darth Malgus thought the Reaper was buried on Ord Radama . Clone Wars . Four thousand years later , during the Clone Wars , Count Dooku and his mercenary Cydon Prax scoured Raxus Prime for the Force Harvester . It was a vital part in reconstructing the Dark Reaper to destroy the Galactic Republic . He used Cydon Prax to activate the Force Harvester , destroying the forest on a Kashyyyk moon as a test of its power . To test its power , he planned to use it on captured Wookiees , Bera Kazan , and Anakin Skywalker , whom he ' d captured on Raxus Prime . The wave of energy given off killed half of the thriving forest on the moon . Anakin and Bera barely escaped the wave , and then contacted the Republic to warn them of what Dooku had uncovered . Dooku then used the Harvester to collect energy on Dac , Agamar , and Bakura . Dooku searched the galaxy and found the pieces of the Dark Reaper . The exact locations are unknown , but Mace Windu stated that it was separated into the farthest reaches of the galaxy , making Outer Rim systems likely choices . Dooku then went to Thule and activated the Dark Reaper in an ancient Sith city on the planet . On Rhen Var , Anakin Skywalker went to the tomb of Ulic Qel - Droma for information on how to withstand the effects of Dark Reaper and the Harvester . Shortly after the Dark Reaper was revived , Anakin led an attack on the city and destroyed the Reaper using his TX - 130 fighter tank , disobeying an order from Obi - Wan Kenobi to wait for backup . Although Anakin did manage to destroy the Reaper , the knowledge he gained from Qel - Droma caused him to act more arrogantly towards Obi - Wan , and indirectly led him to take a step towards the path to the dark side of the Force .