Sylwin, a Jedi Master of female gender, served at a Jedi temple located on the planet of Batuu in the High Republic Era. Her Padawan, Ady Sun'Zee, was also stationed there. Her death occurred when the Ancient Sith Runestone that they had transported to the temple was unintentionally triggered. Ady, for a short time, thought she was responsible for Sylwin's death due to the runestone's influence, but Master Yoda clarified that this was not the case.