A Human female hailing from the planet of Kesh, Nida Korsin rose to become the Grand Lord of the Lost Tribe of Sith, a dark side order. She was born to Lord Yaru Korsin and Seelah, his wife, into a complicated family situation. Yaru had killed Seelah's previous husband some years prior to Nida's birth, and Seelah married him to safeguard her and her son's future, all while plotting Yaru's demise. Despite Seelah's attempts to prevent Korsin's training in the Sith arts, Korsin secretly learned the dark side through her father's clandestine instruction and was prepared to take his place. Known for her love of uvak riding, she was put in charge of the Skyborn Rangers riding club, which doubled as a military force ready to suppress an expected armed rebellion by Seelah and her son, Jariad. This uprising occurred in 4975 BBY. Although Yaru was mortally wounded during the battle, Korsin and her Skyborn Rangers reversed the situation and crushed the coup attempt. Subsequently, Korsin became the new Grand Lord, beginning a golden era for the Lost Tribe. She passed away without an heir in 4896 BBY, after a seventy-nine-year rule, which brought an end to the dynastic succession system within the Lost Tribe.
Nida Korsin, a Force-sensitive Human female, was born on the isolated planet of Kesh in 4995 BBY, the daughter of Yaru and Seelah Korsin. Both of Korsin's parents were members of the crew of the Sith starship Omen. In 5000 BBY, while on a Lignan mining expedition during the Great Hyperspace War, the Omen crash-landed on Kesh following a Jedi attack. The survivors of the Omen established a planetary government as a new Sith organization, known as the Lost Tribe of Sith, with Korsin's father, the former captain of the Omen, becoming the Grand Lord. Seelah had been married to Yaru's half-brother, Devore, who also survived the Omen crash, but was later killed by Yaru after attempting to seize power. To secure her and her son Jariad's positions, Seelah married her husband's murderer and gave birth to Nida, all while secretly planning Yaru's downfall. Despite Korsin being Seelah's only daughter, her mother viewed her as a mere genealogical detail and actively tried to limit Korsin's training in the Sith ways, instead preparing Jariad to become the next Grand Lord.
In what appeared to be a sign of Sith trust in the native Keshiri, the young Nida Korsin was placed in various Keshiri villages with Keshiri nurse-maids and tutors, hindering her from receiving any substantial training in the dark side of the Force. However, Yaru circumvented Seelah's plans. The Grand Lord faked the deaths of several loyal subordinates who secretly taught Korsin during the night. During the day, Korsin, who became a skilled rider of the avian uvak beasts native to Kesh, acted as an aerial ambassador among the Keshiri, allowing her to gain friends among the natives and establish an informant network. Unbeknownst to her mother, she was secretly being groomed to eventually take control of the Lost Tribe.
In 4975 BBY, for Korsin's twentieth birthday, she was appointed leader of an uvak-riding club called the Skyborn Rangers. While appearing to be just a group of hobby riders, the Skyborn Rangers were actually trained Sith warriors secretly prepared to defend Grand Lord Yaru in the event of an anticipated armed uprising by Seelah and Jariad. Although the Lost Tribe had attempted to find a way off Kesh over the past twenty-five years, they had since given up and committed to living among the Keshiri permanently. Their intentions were announced during a large celebration in the capital city of Tahv, featuring a grand entrance on uvak-back by Korsin and her Rangers, which received a mixed response.
As the leader of the Skyborn Rangers, Korsin developed a close relationship with the group's traveling stable master, Tona Vaal, the son of Korsin family friend Adari Vaal. Korsin soon discovered that Vaal was a member of a Keshiri resistance group led by his mother, which was preparing to strike and carry out their plan to overthrow Sith rule. Their scheme involved stealing thousands of uvak vital to Sith control, which would be sent to their deaths to provoke an armed uprising. However, Vaal fell in love with Korsin and revealed the details of the plot, allowing her to prevent most of the uvak from being stolen.
At the same time, she and her Skyborn Rangers were summoned for their primary purpose. After foiling the resistance's efforts, Korsin and her companions rushed to the Kesh Sith Temple on uvak-back, where Seelah and Jariad had attacked. Despite Yaru's valiant defense, Korsin arrived to find her father wounded and cornered. Activating her lightsaber, Korsin joined the battle, and she and her Rangers turned the tide. In a final act, Yaru attempted to push Jariad off a cliff, but when he failed, Korsin completed the task, killing her brother. Seelah was wounded and rendered unconscious in an explosion, losing the use of her legs. With his dying breath, Yaru entrusted his legacy to Korsin, a decision ratified by the three surviving Sith High Lords, officially making her the new Grand Lord.
In the initial hours of her reign as Grand Lord, Korsin made several declarations in accordance with her father's final wishes: from then on, the spouse and household servants of the Grand Lord, excluding Seelah, would be executed upon the ruler's death. In Seelah's case, Korsin ordered the immediate withdrawal of the Sith from the Temple, leaving her mother to live out her days alone. When Seelah awoke hours after the battle, Korsin was by her side to deliver the news.
Korsin also received another gift from her father: a map of a previously unknown continent far across the sea, discovered through examination of the last visual data recorded by the Omen twenty-five years earlier. Aware that the continent was inhabited, Korsin vowed to keep its existence a secret, only revealing it when the people truly needed to know. She went on to have a celebrated reign as Grand Lord, ushering in a golden age for the Lost Tribe. She eventually married a man who became her Lord Consort, and in 4960 BBY they had a son, Donellan. Although Donellan was in line to succeed his mother, Korsin outlived her son, who had waited too long to make his move. Without an heir, she abolished the dynastic system, replacing it with succession based on merit. Korsin reigned for seventy-nine years—a record still standing as of 3000 BBY—and died in 4896 BBY. In honor of her rule, the Festival of Nida's Rise, held every seventy-nine years, was established. By 3000 BBY, Korsin and her father were the most revered figures on Kesh, depicted in statues and monuments throughout the land.
Despite her seemingly harmless and somewhat clumsy appearance, Nida Korsin was secretly a cunning and capable Sith leader. She possessed charisma and easily won people over, gaining the loyalty of numerous friends and informants, as demonstrated by her charming of Tona Vaal, who subsequently revealed the Keshiri resistance's hidden plans to her. Actively involved in the community, Korsin cultivated a public image of being rugged and lively, publicly leading the Skyborn Rangers and wearing clothes that reflected this image. As Yaru's heir, Korsin was deeply loyal to the Grand Lord, rescuing him from Seelah and Jariad's attack. Conversely, she mirrored her mother's coldness towards herself, abandoning her to die alone in the isolated Kesh Sith Temple.
Despite her mother's efforts, Nida Korsin secretly learned the dark side of the Force, eventually becoming skilled in the ways of the Sith. She was also extremely proficient with a lightsaber, easily defeating Seelah and Jariad's forces in the battle near the Kesh Sith Temple. Korsin was also a skilled uvak rider, an ability she utilized in her role with the Skyborn Rangers. Following her father's death, she proved to be an excellent leader and governor, leading the Lost Tribe of Sith into an unprecedented golden age.
Nida Korsin was first mentioned in Lost Tribe of the Sith: Paragon, the third eBook in John Jackson Miller's Lost Tribe of the Sith series, but she made her first appearance in the series' next installment, Savior. Korsin was also mentioned in four subsequent sequels: Purgatory, Sentinel, Pantheon, and Secrets, and was also referenced in the 2012 reference book The Essential Reader's Companion.