Sylvie is an exceptional Valkyrie II variable fighter pilot and commander of the Faerie Squadron who, despite her young age of 17 years old, ranks highly as a pilot, second only to Nexx Gilbert. She inherited her combat skills from her Meltrandi grandmother. When she learns about Marduk's use of brainwashing on their Zentradi soldiers, Sylvie becomes enraged and takes action against them. Initially, Hibiki and Sylvie had a rocky relationship due to the latter's secret meeting with Supreme Commander Exxegran, which led to Hibiki punching her in the nose. However, as they encountered each other more frequently during the war against Marduk, Sylvie's feelings towards him began to change.