Sylvar was a Cathar Jedi Knight, hailing from the planet of the same name, during the time of the great Sith War. Sylvar and her mate Crado, also a Cathar and Jedi as well, trained under Jedi Master Vodo-Siosk Baas alongside Exar Kun. Master Vodo often taught lightsaber cadences and techniques on the planet of Dantooine amidst its ancient ruins. During one such session, Sylvar was watching her mate, Crado, in a sparring match with Exar Kun, a match in which Kun beat Crado quite easily. Annoyed with Kun's arrogance, Sylvar then engaged Kun in a match herself. During the match however, Sylvar let her anger get the best of her and delivered Exar Kun a blow across the face with her hunting claws, permanently scarring him with three deep gashes.
It was Kun's turn to lose himself to his anger as he returned blows and all but killed Sylvar, who was only saved by Vodo's intervention. Soon after, Kun left the quartet's company on a mission to discover secrets of the Sith. Also, elsewhere in the galaxy, a group calling themselves the Krath, operating out of the Empress Teta System, had declared war on the Jedi, and a convocation of all Jedi was called for to discuss this growing threat. Sylvar accompanied Vodo and her mate Crado to the planet of Deneba to meet with other Jedi Knights and Masters at the convocation. During the journey to Deneba, Crado proposed to Sylvar that once their training is complete, they get married and bear an offspring to raise.
Sylvar accepted Crado's proposal, but also made clear the duty she felt to the Jedi. As the trio was approaching Deneba, Vodo went into a deep meditation in an attempt to help Exar Kun who, Vodo feared had gotten himself deep into trouble. Kun had gotten himself into trouble on the planet Korriban, and agreed to give in to the Dark Side in exchange for the spirit of Freedon Nadd saving him from certain death. Nadd's wishes met, he healed Kun's body, however he did it without sparing Kun from the pain. Kun's scream was heard across the galaxy in the minds of Sylvar, Crado, Master Vodo, and even the Jedi on Deneba.