Arren Kae, remembered for her role in guiding Revan, was a Jedi Master of the female persuasion. Following her exile from the Jedi Order, she stood with her prior student in the Mandalorian Wars, ultimately vanishing near the war's end. She was also the mother of Brianna, an Echani.
Mical indicated that Arren Kae was among the Masters who instructed Revan during his time as a Padawan. In 3951 BBY, the Jedi scholar informed Meetra Surik that she was among the Masters blamed for the Jedi's division during the Mandalorian Wars, and also for the Civil War that ensued. When discussing the past failings of the Jedi Masters, Zez-Kai Ell also brought up Kae, citing Revan's fall to the dark side of the Force. Both Mical and Kreia mentioned Kae's banishment from the Order to Meetra, with Kreia offering additional insight into the reasons behind her punishment. Kreia revealed that Master Kae had secretly maintained a romantic relationship and parented a child for almost a decade, which violated the Order's then-existing rule forbidding Jedi from having offspring. According to her, Kae was banished when her infractions were discovered.
The father of the child was Yusanis, an Echani Senator and General, and a renowned and formidable warrior. After Kae's exile, Revan welcomed her to join the Revanchists, and she fought alongside him against the Mandalorians until the Battle of Malachor V. Yusanis followed her to war, breaking an oath to a person to whom he had pledged himself, and eventually became one of the greatest heroes of the conflict, but he would return alone and forsake battle, serving since as a Senator for his people. Their daughter, Brianna, would later be known as the Last of the Handmaidens, the Echani sisters who served Jedi Master Atris.
It was believed that Arren died at Malachor V during the Mandalorian Wars, although her body was never found. Revan killed Yusanis during the Jedi Civil War in an attempt to destabilize the Echani worlds. Meetra Surik encountered Brianna at the Telosian Jedi Academy and spoke with her, satisfying her curiosity and explaining what it felt like to sense the Force. While serving Atris, Brianna secretly yearned to follow her mother's path and become a Jedi, but like her half-sisters, she had vowed never to learn the ways of the Jedi, despite being Force-sensitive. Kae's sole inheritance to her daughter was her Jedi apparel, which Brianna wore for training as she taught Meetra some Echani training. Brianna eventually broke her oath to Atris and became one of Meetra's followers. After Atris was judged by the new Jedi High Council, she succeeded her as Jedi historian.
Brianna, Kae's daughter, is a playable character featured in the video game Star Wars: Knights of the Old Republic II: The Sith Lords. Her Jedi lineage enables her to be trained in the Force. In the game, Brianna has Kae's Jedi robe as a usable item, which is a white robe that enhances the wearer's Charisma. Echani are also known to strongly resemble their same-sex parent. As such, Brianna is said to have the face of her mother, Arren Kae. If the Exile is played as a male and undergoes Echani training with Brianna, Kreia will recount the story of Arren's exile from the Order, unlocking additional dialogue with Brianna where she discusses her father and how he broke his oath to be with the one he loved. Mical and Kreia both suggest that Kae and Kreia were both Revan's Masters. When asked if Kreia and Kae were the same person, lead designer Chris Avellone responded, "Can't comment, but good catch. Sorry." Avellone has used the phrase "good catch" in the Fallout Bibles to indicate unintended implications he appreciates.
Therefore, it is certainly plausible that Kreia is Kae, as Brianna never saw her mother's face and would not have recognized Kreia as her mother. It is said that Kreia left the Jedi Order, just like Kae. Jedi Master Kavar also mentioned that he thought that she had died in the Mandalorian Wars. Brianna said the same about her mother.
"Arren Kae" is also the name of a character created by Obsidian Entertainment for beta-testing purposes. This character used the PFHC06 portrait, described as a "girl with platinum blonde hair." This reference appears in the dialog.tlk file, where another character, Eras Jast, is also mentioned. Although Brianna will not join female playing characters, Brianna following the Exile became canon when referenced in Star Wars Miniatures: Knights of the Old Republic.