Project Omega, an endeavor undertaken by Rezi Soresh, aimed to engineer the ultimate assassin. The program involved several subjects: X-1, X-2, X-3, X-4, X-5, X-6, and X-7; ultimately, X-7 emerged as the winner, securing the position as Soresh's personal killer. Soresh employed a combination of chemical serums and torture to diminish an individual's resolve and wipe away their past, ensuring complete obedience while preserving the skills needed for hazardous missions.
Around 1 ABY, Soresh believed his technique was perfected. During his banishment on a barren moon, he utilized the project's findings to generate a force of devoted, though less capable, protectors. Subsequently, he attempted to subject the Rebel pilot Luke Skywalker to the process; however, Skywalker managed to feign allegiance. In Soresh's last battle, Skywalker employed the Force to break the guards' conditioning, enabling their escape; Soresh was then blasted by Han Solo.