Sorzus Syn

Once a member of the Jedi, she and her allies departed from the Jedi Order because the Jedi Council forbade their investigations into the dark side of the Force. Due to this prohibition, the Dark Jedi launched an attempt to overthrow the Order, in a conflict known as the Hundred-Year Darkness. Syn, mastering the power of dark side alchemy, rose to become a prominent commander among the Dark Jedi. During the conflict, she functioned as a master summoner and brought into being a number of creatures, including Shamblers, Howlers, Pit Horrors, and Leviathans, with the latter employed to breach Jedi defenses during a battle on Balmorra. However, Syn and the other Dark Jedi were defeated at the Battle of Corbos. Subsequently, Syn and the remaining eleven dark side adherents were forcibly placed on a vessel and exiled.

During the war, Syn gathered intelligence and tales from refugees regarding Sith space and the Sith people, who held unique knowledge of the dark side. As a result, she and the survivors piloted their ship into the unknown, ensuring they would not be followed by the Jedi or the Republic.

After arriving on Korriban, the original world of the pureblood Sith, they made landfall in the Valley of the Sleeping Kings. At first, the Sith, under their king Hakagram Graush, met the Exiles with aggression; however, the Dark Jedi were able to use their superior technology, lightsabers, and Force abilities to overcome their efforts. The Dark Jedi then swayed Graush's Shadow Hand to their cause, leading to Graush's betrayal and execution at the hands of their leader Ajunta Pall, who used Graush's own war sword to carry out the act. Following this, Pall assumed Graush's role as the leader of the Sith. The Dark Jedi, known as "Jen'jidai," became the first Sith Lords, with Pall becoming the first Dark Lord of the Sith. The former Jedi then incorporated the knowledge of the Sith, making it their own, and established the first Sith Empire.

Soon after, Sorzus decided to begin her first journal, entitled "exile and arrival", in which she chronicled the events during the war and after their defeat against the Jedi. In her own view regarding the arrival of the Dark Jedi and the triumph of the Sith, Syn voiced her aspiration to become the new Dark Lord.

Not long after, the Dark Jedi charted the Sith worlds and hyperspace routes. On the throne of the planet Ziost, the Dark Jedi constructed their own palaces and established a Sith Council under the leadership of Ajunta Pall; however, Syn hoped that his reign would be short-lived. In the years that followed, she crafted powerful artifacts, the three Great Amulets, for her fellow Sith Lords, including a talisman for Karness Muur. However, her true plan was to create several more talismans, with the second intended for Muur's rival Remulus Dreypa, and the third, the most powerful amulet, to remain in her own possession. She also determined that the Sith's blood was genetically compatible enough with their own to allow for crossbreeding through alchemical means.

After the Dark Jedi had established themselves on Ziost, Syn journeyed back to Korriban with a contingent of priests and slaves to unseal the ancient tombs. Upon entering the Cloister of Bilious Torment, Syn lost approximately forty of her slaves to ancient, yet still deadly, traps before she could advance further into the temple and gain access to the sarcophagus within. After seven days of attempting to penetrate the ancient complex, Syn entered the sanctuary of Sakkra-Kla, which had been sealed for over 10,000 years; while she lost six additional slaves to a pack of tuk'ata, she also discovered a number of scrolls containing information about Sith Alchemy. She also found the Holocron of King Nakgru, from whom she learned more about the Sith and the rule of their ancestral King Adas.

Subsequently, she sought out some of the conquered Sith worlds to gain further knowledge. Upon seeing a chained Draethos, she realized that she had more to learn within the star maps, to better trace the raids of the Sith. She discovered that, at some point, the Sith did indeed attack the worlds of Draethos, Felucia, and Quermia, among others. Later, Syn studied the breeding pens on Ziost and the creatures housed there, as well as studying Sith alchemy and sorcery, discovering scrolls hidden in the blood slurry of the Mongrel Altar, which was next to the body of Wyrmuk the Undying, whose grave was concealed behind a mural of King Adas. She was able to fight and resist the curses that were imposed on the scrolls to protect them, and study their contents. Syn may have been the author of the Sith Code.

In her journal, Sorzus recounted the story of the Jedi Order's founding on Tython. Following a summary of the Second Great Schism, she expressed her disappointment that the Order had failed to learn from the Renunciates and had reverted to the old ways of the Jedi instead of embracing the dark side. She detailed her perspective on the Hundred Year Darkness, the arrival on Korriban, the origins of Sith culture, and the traditions of the Sith. She also documented her findings on the weapons and artifacts of the Sith, integrating them into the new Sith rule. Furthermore, she discussed her discoveries from the ancient holocrons and her insights regarding the rise of the ancestral King Adas, which spurred her own research into the Sith conquests.

After a section on war beasts, she mentioned Sith alchemy, and explained her findings to the incantations of Sith magic. Along with her group, they compared the codes of the Jedi and the Sith, explaining the prophecy of Sith'ari.

Later on, Syn's journals would be used, together with other chronicles from figures like Darth Malgus and Darth Bane, to create the Book of Sith by Darth Sidious.

Near the end of her life, Sorzus Syn created her own holocron. Jedi, such as Jedi Master Mace Windu, believed that the Jedi Order had successfully recovered her holocron, but in reality, they had recovered a secret spying device concealed by a shrouding spell. The true holocron had been in the possession of the Sith since the era of Darth Bane.

A portion of her journal, beginning from the third month of their exile, remained intact after her death and was included in the archive of the Jedi Temple, where Mace Windu and Grand Master Yoda examined the pages in which she pointed primarily to the dangers of the dark side. Following the Great Jedi Purge, the book came into the possession of the new Emperor Darth Sidious. According to his statement, these statements were the oldest text that lasted for thousands of years. He noted that all the authors collected were Sorzus Syn, Darth Malgus, Darth Bane, Darth Plagueis, and Mother Talzin. They were believed to be strong in their own dogma and were removed from the path that the Sith had. When the book fell into the hands of Grand Master Luke Skywalker, he tried to associate the contributions to their time. He believed that the scriptures were written in the years after 7000 BBY. The entries of the Jedi that he dated to a time before the Battle of Naboo in 32 BBY, and Sidious' remarks, after he seized power in 19 BBY.

During her time as a member of the Jedi Order, Sorzus Syn served the light side of the Force; however, upon succumbing to the dark side, she became callous, self-centered, and power-hungry, displaying a complete disregard for the suffering of others. For instance, she showed no emotion for the slaves who perished during her excavations of Sith tombs, even sacrificing one to a tuk'ata to save herself. As an expert in the creation of biological weapons and plagues, Sorzus Syn discussed various forms and benefits. In her view, using alchemy to alter dead creatures was easier because dead cells, unlike living ones, could not resist.

Sorzus Syn was created by Daniel Wallace and featured in the 2012 publication Book of Sith: Secrets from the Dark Side, as the in-universe writer of a section of the book that described the Sith Purebloods. Wallace's original name for the character was "Sanguinus Syn."