As a youngling, Vaylin manifested such immense power that even her own father was frightened. To gain control over her, Valkorion dispatched his daughter to Nathema, where she underwent a harsh program of mental conditioning. Upon her eventual return, Valkorion gifted her a lightsaber that had a yellow-colored blade and a hilt adorned with Zakuulan designs. Vaylin made use of this lightsaber during her time as a High Justice serving both her father and her brother Arcann, who later took his place as Eternal Emperor. However, she seldom used it, preferring to rely on her substantial strength in the Force, which resulted in her lightsaber combat abilities becoming somewhat underdeveloped.
During her pursuit of the escaped Outlander, Vaylin activated her lightsaber after trapping her target, but then deactivated it, confident that she would not need it. She engaged in a duel with her mother on Asylum using it, only to be caught off guard when Senya managed to disarm her. After SCORPIO seized control of the Eternal Throne, Vaylin stormed into the room, lightsaber drawn, only to switch it off once SCORPIO clarified her intentions and allowed Vaylin to ascend to the Throne. Driven by a desire for revenge against her mother, Vaylin tracked Senya to Ord Mantell, where she ambushed her and engaged in another duel.
SCORPIO took on the role of Vaylin's advisor and assisted her in orchestrating an assault on the Gravestone. During this operation, Vaylin brandished her lightsaber to intimidate captured members of the Alliance, but ultimately decided against using it. At the Grand Festival of Empress Vaylin, her brother Arcann reappeared, having recovered from his injuries, and Vaylin fought him in a duel to defend her claim to the Eternal Throne. Subsequently, Vaylin journeyed back to Nathema, a place that was a Void in the Force. Taken aback by her inability to access the Force, Vaylin was forced to rely on her lightsaber to defend herself against mutated acklays within Jarak's laboratory. Vaylin ultimately met her demise on Odessen, where she engaged in combat with Arcann, Senya, and the Outlander, who was carrying her father's spirit. Ultimately, her mortal form was defeated.