Dark Reaper
this ancient Sith weapon was believed to have been lost, until Count Dooku - known to the Sith as Darth Tyranus - was dispatched by Darth Sidious to locate it, during the early stages of the Clone Wars. The forces of the Old Republic were able to learn of Dooku's mission and intercept him, preventing an possible recovery of the weapon. The Dark Reaper itself was created during the time of the Great Sith War, and was most likely the idea of Ulic Qel-Droma and his fellow Sith. The Reaper itself was a saucer-shaped weapon that required a separate power source - the Force Harvester. Thousands of years later, when the Dark Reaper was to be actived by Dooku, the spirit of Ulic appeared to Anakin Skywalker on Thule. Ulic's spirit explained to the young Jedi how to destroy the device, a task that involved harnessing the Reaper's own energy without being corrupted by it. With Ulic's guidance, Anakin was able to destroy the Dark Reaper, ending the threat it posed to the rest of the galaxy.