There were twelve Sith Lords that were the actual faces of the Sith Empire. While the Emperor and his Wrath remained in the shadows, the Sith Council made day to day decisions that affective the overall path of the Empire. The Council instead of reporting to the Emperor directly, reported to the Regent. These twelve Sith Lords were bounded only by their mutual desires and hate of the Jedi Order - which prevented many of them from constant infighting. However, backstabbing and politics - and sometimes even fights to the death - were not unknown in the Sith Council as most of their violent dealings happened in secret rather than in the open.
Due to the fact that the most powerful of Sith sit on the Sith Council, only those with the title of Darth have managed to hold a seat.
Council Members: Open to twelve
Each Sith Council member was in charge of a different sphere of influence. Because of this, outside of meetings in the council, the Sith Council members would have duties of their own to attend to as well as many servants of their own.
Sphere of Ancient Knowledge
Open to PC Sith
The leader of the Sphere was responsible for the protection and expansion of Sith knowledge. Most of their activities would involve archaeology projects on Korriban, Ziost, and Dromund Kaas to uncover the secrets long forgotten by the current Sith Lords.
Sphere of Biotic Science
Open to a PC Sith
The leader of the Sphere controlled all alchemical and biotic science within the Empire, sharing joint control of the Imperial Science Bureau with the Sphere of Technology. Typically, they would corrupt conquered species with the dark side in order to create a new resource for war. They also frequently attempted to find the limitations of cybernetics and sought to augment the non-Force sensitive troops in their general ranks with such technology.
Sphere of Defense of the Empire
Open to a PC Sith
The leader of the Sphere oversaw the use of the Imperial military in the defense of the Empire, sharing joint control of the military with the Spheres of Military Offense and Military Strategy. They normally were in charge of keeping an inherently unstable Empire together. Because of that, they normally were among the strongest of Sith on the Council that could manage to be the voice of reason that keeps order in their meetings.
Sphere of Expansion and Diplomacy
Open to a PC Sith
The leader of the Sphere was responsible for the expansion of the Empire's borders and all diplomatic relations. The Imperial Diplomatic Service answered to the head of the Sphere.
Sphere of Imperial Intelligence
Open to a PC Sith
The leader of the Sphere was responsible for overseeing the main Intelligence operations of the Empire. They would be in charge of covertly acquiring secret knowledge, both within and outside the Empire. They would also be in charge of assigning wet work to agents, which included assassinations, double agent activity, spying, and many other activities.
Sphere of Laws and Justice
Open to a PC Sith
The leader of the Sphere was responsible for the internal law enforcement and judicial systems of the Empire. While the Sith's sense of justice was strange to most, head of the Sphere had to make such a thing rational to both Sith and the non-Force users that serve the Empire. As a result of many of the laws being inherently oppressive, the head therefore usually embodied the mentality of "might makes right."
Sphere of Military Offense
Open to a PC Sith
The leader the Sphere was responsible for directing the Imperial military on campaigns of conquest, and the Sphere of Military Strategy advised the Sphere on matters of strategy.
Sphere of Military Strategy
Open to a PC Sith
The leader of the Sphere was responsible for the strategies and plans that allowed the Spheres of Military Offense and Defense of the Empire to lead the Imperial Military to victory.
Sphere of Mysteries
Open to a PC Sith
The leader of the Sphere was responsible for the upbringing of Sith assassins within the Empire. The head would typically be the most powerful of Sith assassins. One of the secondary goals of the Sphere of Mysteries was also to stand up to its name by keeping its own activities relatively unknown to all.
Sphere of Production and Logistics
Open to a PC Sith
The leader of the Sphere oversaw the Ministry of Logistics. The Minister of Logistics reported directly to the Dark Councilor at the head of the Sphere.
Sphere of Sith Philosophy
Open to a PC Sith
The leader of the Sphere was concerned with upholding the Sith code among the Sith Order, rooting out sympathizers of the light side and spreading anti-Jedi sentiment.
Sphere of Technology
Open to a PC Sith
The leader of the Sphere was responsible for the scientific advancement of the Empire. The Sphere shared joint control of the Imperial Science Bureau with the Sphere of Biotic Science.