Branches
Sith Marines
They were trained by the Mandalorians, armed by the Zygerrians, and led by the Sith. With their fierceness in battle and fervor to their emperor unmatched, the Sith Marines are quite possibly among the most elite soldiers in galactic history. They are a multi-purpose army, and have been hardened not only by two years of war but constant warring between desolate tribes before that on the harsh terrain of Moraband. With this in mind, it should be no surprise that, when unified, the Sith army modernized so quickly and manage to topple the age-old Republic. In recent years, though, the army has become uncharacteristically idle with the lack of a great threat in peacetime.
Imperial Inquisitors
After the war, many of the Sith went on to help maintain the peace. These Sith became inquisitors, lawmen that maintain order and govern on behalf of the emperor. Security agents have recently joined the inquisitors in their duties and while they are not considered true inquisitors by the Sith, they carry out many of the same duties.
Sith Stalkers
The name Sith Stalker befits the assassins of the Sith Empire. They are rarely, if ever, seen by the public and their very name is almost synonym to myth. However, they are anything but. They are very real and while their origins remain ambigious, they were one of the first tribe of Sith to concede to Darth Ruin. It is said that the Sith Stalkers have the capability to bring down entire empires. Whether or not that is true, they are never seen until it is far, far too late.
Important Figures
Darth Ruin
Darth Ruin is the supreme sovereign of the Sith Empire and the most powerful of the Sith. Few would recognize him as the polite diplomat and quiet scholar that had served the Jedi Order so many years ago. Contrary to popular belief, though, Ruin is not a supremely-powerful being; he simply knows how to pick people to do his dirty work and utilize them to best serve him. Though his combat prowess shouldn't be understated, his real talent lies in the manipulation of others on a massive scale, which, in many ways, is more dangerous than just one man with a lightsaber...
Darth Bellicus
Darth Bellicus was once a Republic hero and war leader of the Great Zygerrian War. However, his return from the war was not met with welcome but with betrayal and Bellicus was exiled from the Jedi Order. Bellicus served as military governor of Zygerria for some time until he abdicated and exiled himself. In unknown space, he met Darth Ruin, who took the wayward Jedi as his first apprentice. Bellicus went on the seethe in his anger for the Jedi, and prepared himself for what he was best at--war. Going as far as fitting himself with cybernetic prosthetics to improve his fighting ability. The apprentice got his wish as he led the charges against the Republic as Ruin's greatest general.
It was at Tython that Darth Bellicus got his revenge against the Jedi as he slew the Grand Master of the Order in combat. However, in a twist of irony, the Sith Lord was betrayed by Ruin who no longer had any use for the general. Replacing Bellicus on the form of a young prodigy, the emperor had determined a loyal child with great potential than an old wardog whose potential had been spent. Although Bellicus was killed (officially, his records ambigiously say he was killed during the assault), his name lives on. To the Sith, he is remembered as the heroic general but to the rest of the galaxy, he is remembered as a villainous butcher...
Darth Arrax
Well over two hundred years old, Arrax was one of the first to ally with Ruin and helped him establish his Sith kingdom. For this reason, Arrax was the first after Ruin awarded the honorary title of 'Darth' and given the prestigious rank of the High Prophet, the emperor's most trusted advisor. Darth Arrax possesses great wisdom, and it is believed the pureblooded Sith also possesses the power of foresight. This does bring the question of Arrax's loyalty, as if he was supposedly able to foresee Sith's rise and allied with him, will he still stay if he witnesses the Sith's fall...
Darth Viska
Sharp and talented, the young Darth Viska arose from bottom to top as one of the Sith academy's brightest pupils and the empire's most skilled inquisitors. Her exceptional talent caught the eye of the emperor who made her the Grand Inquisitor, the primary enforcer of his law...
Master of the Sith Stalkers
The Master of the Sith Stalkers, known to few as Sicarius, is a mysterious man. An imposing figure, Sicarius is believed to have been an Ubese assassin submitted to horrific experiments which made him into a cybernetic monstrosity by those who know him. Very few, however, even know of his existence. He has become known to the common people as a myth called 'the Shadow'. This is because you never see him until is far too late...
Darth Troyer
Ephas Leroun is the prized apprentice and prime enforcer of the emperor. Initially Ruin's Jedi apprentice, Leroun was trained in secret while veteran fighters such as Darth Bellicus fought the war. During the conflict, Ruin tested his apprentice's prowess by sending him on covert operations that were too small to be handled by Bellicus. Eventually Leroun was tested during the fall of the Old Republic, when Bellicus's forces attacked the Jedi Temple. Ruin had ordered his apprentice to raid the Jedi Archives and to eliminate Bellicus. The two had their showdown in the Jedi Council chamber, where the young Jedi bested and slew Bellicus, solidifying his place as Ruin's apprentice. When Ephas returned, he was given Bellicus's estate, title as the military commander of the Sith Empire, and renamed Darth Troyer.
Hierachy
Emperor of the Sith
Hand of the Sith
Sith Lord
Apprentice
Acolyte
High Governor
Sector Governor
Planetary Overseer
General
Commandant
Trooper