- "Go, Asyr, go now. Waiting around is just gonna get you killed."
- ―Wedge Antilles
As a youth, Sei'lar enrolled in the Bothan Martial Academy against her parents' wishes. She was trained in flight combat along with Peshk Vri'syk, another future Rogue Squadron pilot. The two were equals during training, but because he graduated one year ahead of her, he was able to join the elite squadron first.
She later ended up on Coruscant, where she joined the anti-Human Alien Combine organization. There she met Tatooinian Rogue Squadron pilot Gavin Darklighter. At first, she took him for an anti-Alien bigot and turned him over to the Combine for execution, but later reconsidered and joined the Rogues. She took part in the liberation of Coruscant on their side, and she and Gavin also soon fell in love.
She continued to fly with Rogue Squadron for several years, flying during the Krytos threat and later resigning with the rest of the Rogues to wage the Bacta War against Ysanne Isard's Thyferra. She survived Thrawn's campaign against the New Republic and was a source of great pride for her home world of Bothawui.
Her relationship with Gavin Darklighter later caused problems, as fellow Bothan and New Republic Senator Borsk Fey'lya opposed it due to Darklighter being Human. During Ysanne Isard's return, Sei'lar was presumed dead in the Battle of Distna of the campaign aimed at ousting Prince-Admiral Delak Krennel in the Ciutric Hegemony. She in fact survived and, with the help of Booster Terrik, decided to go undercover and work toward changes in Bothan society. However, as late as 25 ABY, Gavin still believed her to be dead. Sei'lar kept in contact with Iella Wessiri for a few years, until the reborn Emperor's appearance.
- X-Wing: Wedge's Gamble (First appearance)
- X-Wing: The Krytos Trap
- X-Wing: The Bacta War
- X-Wing: Iron Fist
- X-Wing: Solo Command
- X-Wing: Isard's Revenge
- The New Jedi Order: Dark Tide I: Onslaught (Mentioned only)
- "Who's Who in Rogue Squadron"—Star Wars Insider 59
- The New Essential Guide to Characters
- Coruscant and the Core Worlds
- Ultimate Alien Anthology
- The Complete Star Wars Encyclopedia