Darth Decimus, a Human male, held the esteemed position of Dark Lord of the Sith within the reestablished Sith Empire during both the Cold War and the Galactic War. Furthermore, he presided over the critical Sphere of Military Strategy.
In the waning months of the Great Galactic War, Decimus ascended to the ranks of the Dark Council. This promotion occurred after a Jedi Strike Team successfully eliminated the Dark Councilor Darth Azamin within his clandestine fortress. Subsequently, all Jedi involved in the operation perished when their escape vessel, likely sabotaged, suffered a catastrophic mechanical failure and exploded. Whispers circulated, suggesting Decimus had betrayed Azamin by providing information to the Jedi, though these allegations were never substantiated.
While serving on the Dark Council, Decimus selected Krovos as his apprentice, impressed by her performance during her final trials on Korriban. During these trials, she fostered collaboration among her fellow Sith Acolytes instead of encouraging individual competition, resulting in the survival of all participants.
Decimus was handpicked to spearhead the Imperial invasion of Corellia, devising a strategy that enabled the Empire to seize control of the planet with minimal opposition. He strategically established his headquarters within the former offices of the planet's Trade Tariff Service, a location rendered obsolete and therefore unlikely to be targeted militarily. He transformed it into an Imperial Fortress, christened Decimus's Rise. Under his command, the Imperial forces decimated the majority of the Green Jedi. Following the successful Imperial occupation, he bestowed the Medal of Imperial Glory upon those who had contributed to the victory. However, the Republic later launched an assault and reclaimed Corellia. During the ensuing conflict, Decimus met his end in the Speaker's Garden of the Corellian Legislature Building.
Decimus was celebrated for his exceptional military planning and his talent for leveraging situations to his advantage. Despite his boundless ambition, Decimus maintained unwavering loyalty to the Sith Emperor.
Darth Decimus wielded a single-bladed Sith lightsaber. His prowess as a Sith Warrior in combat was widely recognized, placing him among elite Sith warriors such as Darth Malgus and even Darth Marr.
In the Imperial Corellian Story Arc, Decimus's spoken lines, particularly his initial dialogue, adapts based on the player's chosen class, often offering assistance against the ultimate adversary of their individual class narrative.
The voice of Decimus is provided by Welsh actor Mark Lewis Jones, who also played the role of Captain Moden Canady in Star Wars: Episode VIII The Last Jedi.