Sylia Stingray (spelled Silia in Bubblegum Crisis) is the 24-year-old ringleader of the Knight Sabers. Very calm and cool-headed, she does not show much emotion. She is the daughter of Dr. Katsuhito Stingray, the man who originally created the boomers. He was murdered by Genom executive Brian J. Mason, and his death was covered up as an accident, but an unknown individual managed to send Sylia a data unit, providing her with Genom's future plans and the technological means of creating the Knight Sabers' hardsuits. She wears a blue and silver Hard Suit equipped with retractable sword blades in the forearms, laser cannons in the palms and wings for full flight capability.

Professionally, Sylia is a wealthy businesswoman whose business ventures, aside from the mercenaries' fee, finance the team. Her primary business is the lingerie shop "Silky Doll" she personally runs, housed in her private building, Lady's 633, on whose top is also her penthouse apartment functioning as the Knight Sabers' base of operations. Her civilian vehicle is a red Mercedes-Benz 300SL Gullwing coupe.