Darth Mekhis forged a Sith Knight army by twisting imprisoned Jedi through her dark power and the perversion of science. During the time of the Cold War, Darth Mekhis presented captured Jedi from the Great Galactic War with a choice: willingly join the Sith or face a different fate. Upon their refusal, she transformed them into cybernetically enhanced Sithspawn slaves, beings unrecognizable from the Jedi they once were, thus becoming her Sith Knights. These Jedi were captured by the forces of the reconstituted Sith Empire's.
These creations, once humanoid, were augmented with cybernetic plating and possessed two prominent red eyes. Darth Mekhis, the Dark Lord of the Sith, created a legion of these beings by corrupting and altering captured Jedi through her power and twisted science. Those Jedi who rejected the Sith path were transformed into the dreaded Sith Knights, serving as extensions of their master's will. This transformation meant that these Jedi were completely changed from their former selves.
Initially, the Sith Knights displayed no obvious weaknesses. These warriors were armed with weapons similar to electrostaffs and equipped with stealth field generators, rendering them invisible to the unaided eye. They also possessed sensors, although these systems were susceptible to disruption in irradiated environments.
The Sith Empire, after centuries in hiding, resurfaced during the Great Galactic War to inflict destruction upon the Galactic Republic and the Jedi Order that had nearly vanquished them. During this period, Dark Councilor Darth Mekhis managed to capture a number of Jedi. These prisoners were given a simple choice; either dedicate themselves to the dark side of the Force or be grafted into her machines. Those that refused to join were thus converted into Sith Knights with no trace of their former selves remaining. The conflict ended with the signing of the Treaty of Coruscant, which ceded seven seemingly insignificant worlds to the Empire in exchange for peace, forming the Black Sectors. Among these was the Vesla system, gifted to Darth Mekhis for her dark experiments. Following the war, Jedi Master Ngani Zho lived within the Vesla system for a decade, fighting against her dark schemes and witnessing countless atrocities, including the Sith Knights, which scarred his memory, leaving him with only fragmented recollections of his time there.
After Zho departed the Vesla system during the Cold War, Darth Mekhis dispatched her agents to hunt down the Jedi Master, intending to eliminate him. She sent a trio of her Sith Knights from the Javelin Dreadnought, hoping to inflict the same pain on him that his apprentice Satele Shan had caused Mekhis during the war. The cybernetic creations tracked their target to the planet Taris. While sharing stories with a crowd, the elderly Jedi Master encountered Theron Shan, an agent of the Republic Strategic Information Service tasked with retrieving Zho. As they left the area, the Jedi Master and Shan sensed cloaked figures following them. The RSIS agent deployed a grenade that generated an energy pulse, disrupting the Sith Knights' stealth fields. As the Sith Knights pursued the pair into the tunnels of Taris, Theron and Zho attempted to reach Theron's ship, narrowly escaping a Sith Knight's grasp thanks to Teff'ith, who used a blaster to force the cyborgs back. One Knight managed to land onto the ramp of the starship and the lightsaber of Nghani Zho was used to throw it off leading to the cyborgs failing in their initial assignment.
A contingent of Sith Knights served as Darth Mekhis' personal guard aboard the Sun Razer in the Vesla system. They were deployed to confront Theron Shan after he escaped captivity and attempted to disable the shields protecting the Sun Razer from the star it orbited. The Knights managed to capture Shan, but he used a stun dart to incapacitate Darth Mekhis, and the Sith Knights were accidentally shot by a Imperial soldier. The defeated Sith Knights allowed Theron Shan to complete his objective and destroy the Sun Razer, enabling his escape from Imperial space.