The military of the Sith Eternal encompassed various divisions of the Sith Eternal, including the Final Order and the Sith Eternal army. This military force, a product of the twisted machinations of Galactic Emperor Darth Sidious, was secretly constructed on the dark planet Exegol before 35 ABY. Its purpose was to ultimately replace the established Imperial Military and the First Order military.
However, the Sith Eternal military failed to achieve its intended goals. In a fierce conflict against the Resistance and the Citizens' Fleet during the Battle of Exegol in 35 ABY, Darth Sidious' formidable forces suffered defeat in their inaugural and concluding engagement. This followed the demise of the Dark Lord of the Sith and the destruction of their flagship. Stranded on Exegol and deprived of leadership, the Sith Eternal military effectively disintegrated, prematurely ending what was perhaps the galaxy's most significant threat.
The military of the Sith Eternal was established on Exegol using resources supplied by corporations such as Kuat-Entralla Engineering and Sienar-Jaemus Fleet Systems. These corporations had directorates infiltrated by Darth Sidious' Sith loyalists. The military personnel consisted of young humans who were raised on the Sith world following the fall of the Emperor in 4 ABY.
Prior to Kylo Ren's's arrival, the Final Order, a fleet, was assembled on Exegol. This division of the military was intended to assist the Sith in creating a new Sith Empire that would dominate the galaxy. The fleet comprised more than a thousand Xyston-class Star Destroyers, each equipped with axial superlasers capable of obliterating entire planets, along with thousands of TIE/dg starfighters.
The Sith Eternal army included Sith troopers, Sith Jetpack Troopers, and the distinguished Sovereign Protectors. They made use of advanced AAL-2100/9.5 atmospheric assault landers. The Sith troopers were organized into legions named after ancient Sith Lords, whereas the Sith jet troopers were grouped into squads named after Sith weaponry.
The galaxy witnessed the unveiling of this military force through a demonstration of its destructive capabilities. The Derriphan, a Xyston-class Star Destroyer belonging to the Final Order, employed its axial superlaser against the Mid Rim planet Kijimi, resulting in the planet's devastation on a scale comparable to the Death Stars' and Starkiller Base's superweapons. This display highlighted the true strength of the military force and demonstrated the Sith Eternal's capacity and willingness to annihilate entire planets that defied the Emperor's rule.
The Battle of Exegol resulted in significant losses for this military. The Resistance and their allies, the Citizens' Fleet, emerged victorious after confronting the resurrected Emperor, who also perished on that world at the hands of his granddaughter.