Lene Kostana, a Jedi Master of the Jedi Order, was a Force-sensitive Altiri female. She lived before the Invasion of Naboo. Her Order gave her the task of locating and scrutinizing ancient Sith relics, to prepare for the Sith's eventual return. As Kostana gained more influence within the Jedi Order, the young Dooku became deeply interested in her and her work.
Born to Galdrim and Sula, Lene Kostana was an Altiri female whose birth took place during the High Republic Era. She resided on the planet Temerancé and was abducted by the Nihil during one of their raids because of her connection to the Force. Later, Sula requested that Ty Yorrick, a mercenary, save Lene and the other children captured by the Nihil, which Yorrick successfully accomplished. Eventually, she became a member of the Jedi Order and achieved the rank of Jedi Master. At some point, she developed a strong interest in finding and analyzing Sith artifacts to prepare for the Sith Order's inevitable return. Her belief that the Sith would return, and her obsession with locating and studying Sith artifacts, put her at odds with Grand Master Yoda and the Jedi High Council, who disagreed with her views. Yoda, in particular, did not think finding relics was necessary and disagreed with Kostana's view that younglings and Padawan learners should be prepared for the Sith's potential return. Initially, the young Jedi Dooku thought she might be aligned with the Sith due to her fascination with Sith relics.
Later, Kostana chose Sifo-Dyas as her Padawan (much to Dooku's initial disappointment, as he had hoped to be chosen). The two of them once went on a mission to infiltrate a smuggler operation on Karazak. Kostana and her apprentice wanted to follow their supply routes to find the location of any Sith relics being sold on the black market. However, they were lured into an ambush on Asusto, set up by the last remaining members of the Presagers of Hakotei.
Lene Kostana also served as a mentor to the young Dooku, and once used the fictional character Darth Sakia as a lesson to test the young Jedi. Later, she told Dooku that Sakia had used a curved-hilt lightsaber.
Soon after Kostana taught Sifo-Dyas how to open his mind to the Cosmic Force, the young Jedi began to experience Force visions. One of these visions, which showed a planet engulfed in flames, turned out to be a warning about the coming Protobranch solar storm before it even happened. Kostana encouraged Sifo-Dyas and Dooku to take Sifo-Dyas's visions seriously, but she also tried to hide her apprentice's abilities from the Jedi Council, fearing they would see his talent for foresight as dangerous. Her fears grew even after Sifo-Dyas became a Jedi Knight, when she learned that the Jedi had opened a new correctional unit in the Citadel prison for Jedi with foresight.
Around 82 BBY, during his time as a Padawan, Kostana, Dooku, and Sifo-Dyas attended the funeral of Dooku's mother, Anya, on Serenno, despite the Jedi High Council's objections. Afterward, the three Jedi traveled to Hakotei to find a relic, where they encountered a dark-side sect. This led to Dooku's brief capture for use in a ritual. Dooku experienced several visions of his future and unknowingly used Force lightning to free himself and his Jedi companions, leaving Kostana to comfort Dooku, who was terrified by the visions he had seen.
Some years after Dooku's second apprentice, Qui-Gon Jinn, was knighted, Kostana and Sifo-Dyas agreed to help Dooku liberate Serenno from Abyssin raiders. This mission went against the wishes of the Jedi High Council, who had decided to follow the Galactic Senate's decision not to help Serenno because they had not paid their seasonal taxes. Ultimately, the three Jedi succeeded in driving the raiders away, and Dooku defeated his brother Ramil. However, after the battle, Dooku chose to reject Kostana's suggestion to seek help from the Republic, instead deciding to help the Serennians rebuild as their new leader. Kostana was disappointed by Dooku's choice but accepted it.
Cavan Scott created Lene Kostana, and she first appeared in the 2019 audiobook Dooku: Jedi Lost, written by Scott, with Carol Monda providing her voice. Her first visual depiction was in the second issue of the comic miniseries Star Wars: The High Republic Adventures – Saber for Hire, written by Scott, with illustrations by Rachael Stott and Nicola Righi, published by Dark Horse Comics on May 29, 2024. Dooku: Jedi Lost told the story of Dooku's past. Scott wanted to give Dooku another mentor figure besides Yoda, his established Jedi mentor. Instead of bringing back Thame Cerulian, who was Dooku's Jedi Master in the Star Wars Legends continuity, Scott created Lene Kostana. Although she did not practice the dark side of the Force herself, Kostana was intended to be a factor in Dooku's eventual corruption.