Cyslin Myr, a Mirialan adept in the Force, held the rank of Jedi Master and served as the mentor who trained the Padawan who would become Mace Windu. She recognized his Force-sensitive nature and guided his early development.
Approximately in 60 BBY, Myr and her Padawan embarked on a journey to Mathas, a planet afflicted by the devastating Niffin plague. Working in unison, they exposed and apprehended a charlatan named Drooz. He had been deceiving the local population by posing as a Jedi prophet and healer, extorting them for spiritual guidance. After Mace Windu, her Padawan, neutralized Drooz by taking his weapon and intending to execute him, she intervened and convinced Mace that justice should be served through legal channels, resulting in Drooz's arrest.
The character of Cyslin Myr made her debut in the fourth issue of the Star Wars: Jedi of the Republic – Mace Windu comic book miniseries, released in 2017. Within Star Wars Legends continuity, the Jedi Master responsible for training Mace Windu was the Neti known as T'ra Saa.