Imperial Sith Acolytes were elite force sensitive soldiers deployed by the Galactic Empire in 1 BBY, founded by Dark Lord of the Sith and Galactic Emperor Darth Sidious.
Imperial Sith Acolytes were trained on Kamino as part of the Acolyte Program and frequently worked alongside the Imperial Saber Guards. They quickly gained a reputation for their aggressive training techniques, characterized by their resistance against most force techniques, as well as their ability to channel the Force for destructive purposes. It is unknown whether they were recruited from Force-sensitive Imperials, or whether they were stable clones of the late Galen Marek. It is possible that their number comprised members both Human and clone.
Many Acolytes were deployed to newly subjugated worlds such as Cato Neimoidia, others were stationed on Kamino. A few Acolytes participated in the assault on the Salvation, the flagship of the fledgling Rebel Alliance, during the Assault on Kamino. Starkiller, a renegade clone of Marek, killed many of the Sith Acolytes in his quest to find Rahm Kota and ultimately Juno Eclipse.
The Acolyte program was created shortly after the demise of the original Starkiller. After Galen Marek's infiltration of the Death Star, Emperor Palpatine instigated the program for more protection. The Emperor's apprentice, Darth Vader, used the program as an excuse for the Empire to return to Kamino, and experiment with cloning his apprentice. The Acolytes, wearing red stormtrooper chestplates and armor similar to the Saber Guard, received extensive training in the Force from unknown Dark Side Adepts (or possibly Vader himself), in the Timira City Cloning Facility. The first batch of these warriors were stationed on Cato Neimoidia and were assigned to serve under the command of Baron Merillion Tarko.
During their training, the Acolytes exhibited a murderously sadistic sense of humor, repeatedly using their Force powers to stage "accidents" around the facility, heedless of the personnel injuries and deaths that they caused. Not over familiar with the Force's applications and ignorant as to the main purpose of the Acolyte program, the hapless facility workers could do nothing but wonder what had caused the "accidents", though the fact that the Acolytes were always around when they occurred did make at least one Imperial suspicious.
Despite their training, the Sith Acolytes were ultimately overpowered by Starkiller, a rogue clone of Marek who escaped from Kamino in order to find Captain Juno Eclipse—the woman with whom Marek fell in love prior to his death. During his time on Cato Neimoidia, Starkiller single-handedly annihilated all of the Acolytes that stood in his path. He then rescued the Jedi general Rahm Kota from the Tarko-se arena.
Shortly after the events on Cato Neimoidia, the Acolytes and other Imperial units—including Saber Guards—boarded the Rebel flagship Salvation during the Rebel invasion of Kamino. Despite their capture of the hangar, engine room, and various gun emplacements, the boarding parties were systematically wiped out by Starkiller. Many Acolytes also perished in the fighting throughout Timira City while the rest of their Imperial comrades suffered high casualties against Starkiller and the Alliance. Their failure to defend Kamino ultimately resulted in a major victory for the Rebellion, as well as the capture of Darth Vader.
Imperial Sith Acolytes displayed adequate ability in the Force. They utilized a set of Force techniques which made them nearly impervious to Force attacks. Acolytes were also able to generate abilities such as Force push, Force lightning, and Force repulse. However, their sole focus on utilizing Force-based attacks left them extremely vulnerable against individuals trained in lightsaber combat.