The Sith Eternal army, alternatively referred to as the army of the Final Order, represented the land-based military arm forged by the Sith Eternal in their endeavor to reclaim the galaxy and realize their ultimate ambition: the resurgence of the Sith Order. These combatants were secretly amassed, their existence concealed from the majority of the First Order, which they covertly manipulated. The Sith Eternal army stood as the realization of a complex strategy designed to establish the enduring dominance of a revitalized Sith Empire.
This army of the Sith Eternal was composed of numerous legions filled with elite and devoted Sith troopers who embodied the essence of a deep-rooted and ancient Sith heritage. This military force played a significant role in the crucial Battle of Exegol, where the Sith Eternal's warriors, accompanied by a fleet—the Final Order—of Sith Star Destroyers, clashed with the Resistance and the combined might of the Citizens' Fleet drawn from across the galactic expanse. The conflict on Exegol culminated in the final death of the Dark Lord of the Sith, Darth Sidious, the complete downfall of the Sith Eternal, and the uprising against the First Order.
The Sith Eternal constituted a substantial cult of Sith loyalists dedicated to resurrecting the Sith Order by retaking control of the galaxy under the guidance of the Dark Lord of the Sith Darth Sidious. To achieve this, the Sith Eternal employed a military force that integrated a vast Sith armada, known as the Final Order, operating in tandem with the expansive Sith Eternal army of Sith troopers.
The Sith Eternal's ground forces were structured into different kinds of military formations. In general, the army was arranged into legions, adhering to the historical size of 5,000 soldiers. These legions were managed by Sith trooper officers holding the rank of commanders. The legions were further broken down into squads consisting of ten soldiers, each led by a sergeant. Each squad was then divided into three triads, which were fireteams made up of three soldiers. The triads were commanded by a lance corporal, who oversaw two corporals. Legions within the Sith Eternal army were identified using a numerical designation alongside the name of a past Sith Lord. Examples of legions within the army included the Andeddu Legion, the Desolous Legion, the Phobos Legion, the Revan Legion, the Tanis Legion, and the Tenebrous Legion.
Another type of unit utilized by the Sith Eternal army was the battalion, with at least the 105th Battalion being operational. Aerial infantry squads were formed of ten soldiers and were named after weapons, such as Lanvorak Squad, Parang Squad, and Warblade Squad.
The entire force consisted of countless Sith troopers, warriors of the dark side secretly bred on the Sith planet of Exegol, situated deep within the Unknown Regions. Building on the Sith's experiences with clone troopers during the Clone Wars, Sith troopers underwent rapid indoctrination and loyalty programming that expanded upon and surpassed the methods used by Kaminoan clone trooper training. The result was Sith troopers who exhibited greater loyalty and were more machine-like than even the stormtroopers of the Sith Eternal's puppet regime, the First Order, who were trained from a young age. Despite bearing the name of the revived dark side sect, Sith troopers lacked the ability to wield the Force. Instead, their red armor projected an aura of fear, echoing blood, Sith lightsaber blades, and the elite soldiers of the Sith-controlled Galactic Empire that once governed the galaxy. As crimson was strongly associated with Darth Sidious, the Sith troopers were regarded as the Emperor's personal guard, setting them apart from the stormtroopers of the First Order and the Empire. The most skilled Sith troopers were elevated to the Sovereign Protectors, an elite guard stationed in the amphitheater around the Throne of the Sith inside the Sith Citadel on Exegol.
The Sith Jetpack Troopers, an elite aerial variant, were considered the next stage in the evolution of jetpack infantry. Their rigorous training and advanced equipment allowed them to execute swift, intelligent, and devastating attacks. They provided effective air support for ground troops, operating alongside standard Sith troopers and proving too small and fast to be targeted by anti-aircraft weapons. While visually similar to First Order jet troopers, the critical difference lay in their discipline, ferocity, and unwavering loyalty to their cause, which instilled in them a fearless aggression.
Sith troopers were equipped with ST-W48 blaster rifles and red FWMB-10B repeating blasters. Sith jet troopers carried F-11ABA heavy blaster cannons, which were exceptionally effective against ground forces. The Sovereign Protectors employed the SP-B50 blaster rifle for both ranged and close-quarters combat.
The origins of the Sith Eternal army can be traced back to the forces of the Galactic Republic and the Galactic Empire. Darth Sidious, the leader of the Sith Eternal, sought to create a Sith Empire enforced by the perfect soldier, one completely devoid of any individuality. Although Sidious initially gained power with the help of clone troopers and Imperial stormtroopers, he viewed their capacity for independent thought as a weakness and aimed to eliminate it in his latest generation of armored soldiers.
Under the direction of Darth Sidious, who had been killed and resurrected during the fall of the Galactic Empire, the Sith Eternal established both an army and a navy. While the New Republic was occupied with consolidating its power, Sidious' followers spent a generation developing a military force aimed at restoring Sith dominance throughout the galaxy. For their army, this resulted in a new generation of soldiers whose loyalty and obedience programming surpassed that of the Republic clone troopers, as well as the Imperial and First Order stormtroopers. Their devotion to the Sith cause was so complete that Sidious believed he had successfully eliminated all traces of the individualism he had observed in their predecessors.
Towards the end of the First Order-Resistance War, Supreme Leader Kylo Ren discovered the Emperor, his cult, and the military they had built on Exegol. As a final test of Ren's worthiness to inherit the new Sith Empire, Sidious instructed him to end the legacy of the Jedi Order by killing the Jedi apprentice Rey. In return, he offered Ren control of the Sith Eternal's soldiers and warships, effectively making the grandson of Darth Vader the new Galactic Emperor.
The Sith troopers were stationed aboard the Sith fleet's Xyston-class Star Destroyers, including the Derriphan, which destroyed the planet Kijimi. The Resistance responded by launching an assault on the Sith Eternal's forces, hoping to prevent the Final Order from leaving Exegol. During the Battle of Exegol, the Resistance's ground forces attacked the Resurgent-class Star Destroyer Steadfast to stop Allegiant General Enric Pryde from successfully navigating the fleet through Exegol's atmosphere. As a result, multiple AAL-2100/9.5 atmospheric assault landers landed on the hull of Pryde's command ship, deploying Sith troopers into battle against Resistance troopers and a company of renegade stormtroopers.
Both factions suffered losses in the ensuing battle; however, the Sith troopers were ultimately unable to prevent the Resistance from destroying the Steadfast. Consequently, the Sith fleet was unable to escape Exegol and was destroyed by the combined might of the Resistance and the Citizens' Fleet. The Sith Eternal's defeat on Exegol triggered an uprising against the First Order across the galaxy.
Within the Star Wars Legends continuity, the brigade strength of the reconstituted Sith Empire's Imperial Army ranged from 5,000 to 7,500 soldiers. This is similar to the strength of the Sith Eternal legion, which is said to be using the ancient definition of a legion.