Syl was a Force-sensitive Human female. Syl was one of Satele Shan's students during the third Galactic War. Shan and her students, including Syl, were all infected by Tenebrae's curse and held within a massive ship by Kira Carsen and Scourge. However, they were released by the Commander of the Eternal Alliance who ended Tenebrae for good. Syl was thought to be dead but miraculously survived the ordeal.
Syl was one of many Force users who became part of a crop of students that Jedi Master Satele Shan started to train at a secret Jedi academy on Coruscant after the war against Zakuul.
Syl seemingly dead on Satele Shan's mindscape
When Satele Shan unknowingly became infected by the plague of the deceased Emperor Tenebrae, Syl and the rest of the followers also became infected. They were all left in a nightmarish sleep before slowly merging into a hive mind. Sith Lord Scourge and Jedi Knight Kira Carsen kept them quarantined in the latter's ship, flying an undetermined course through unsettled sectors of the Outer Rim Territories.
After most of the followers were released from the curse by the Commander of the Eternal Alliance, who ended Tenebrae for good, Syl was believed to be dead like fellow student Trad, but in reality she miraculously survived the infection.
Syl sees Aryn Leneer.
Back on Coruscant after the incident with Tenebrae, Syl watched how the former Jedi Aryn Leneer went to meet with Master Satele Shan. The young student later interrupted their conversation by telling Satele that Master Sal-Deron wanted to speak with her, if she could spare the time, barely glancing at Aryn before she left the room. Both Satele and Aryn briefly talked about Syl after she left before meeting Sal-Deron.
A young Human female with bright red hair, Syl was described by Satele Shan as a complicated student with whom she has to pick her battles wisely. Syl seemed to be very informal, as she addressed her master simply as Satele, which surprised Aryn Leneer.
Syl first appeared in Star Wars: The Old Republic: Onslaught as part of the "Echos of Oblivion" flashpoint, where the student's name was first revealed by Kira Carsen.