Rebus, holding the rank of colonel, spearheaded a research initiative for the reconstituted Sith Empire during the period of the Cold War that existed between the Galactic Republic and the newly arisen Sith Empire. A significant portion of Colonel Rebus's efforts were dedicated to the design of the Gauntlet superweapon, later destroyed with the aid of Havoc Squad. He also contributed to other endeavors, including the Blight Matrix, the Galactophage, Subjugation Droid, and the Plasm Resource. It was rumored that he even conceived of a device capable of disrupting hyperlanes; however, the project was abandoned due to insufficient power capabilities.
Upon receiving intelligence indicating that Colonel Rebus was preparing to evaluate one of his projects, M1-4X journeyed to the location to investigate. Rebus, however, foresaw this and orchestrated an ambush to seize M1-4X's power core. Employing an energy-based mechanism, Rebus proceeded to overwhelm Forex's primary energy regulation systems, thereby immobilizing the droid. Forex, retaining command over a limited number of auxiliary subsystems, skillfully manipulated them to initiate a comprehensive emergency shutdown coupled with a rear servo lock. This action forcefully propelled the droid onto Rebus, effectively disabling his device. While Rebus's security detail tended to the colonel, Forex managed to reactivate his systems after a minute and a half, eliminating the remaining guards. Subsequently, he captured Rebus and returned him to base. The last report regarding Rebus indicated that, while undergoing treatment for his injuries, he had a "nonzero chance of speaking or walking again."