Sylvia starts as Joe's girlfriend, an ordinary young woman with no powers or cinematic ties. During a movie date, she is snatched by a villain emerging from the screen, triggering the core conflict. Her background reveals she is the daughter of the superhero Captain Blue and has a twin sister, Goldie, largely referenced outside Sylvia's direct narrative in supplemental stories. Rescued by Joe in the first major conflict, Sylvia transitions from captive to active participant. She reconciles with her father, Captain Blue, and persuades him to grant her a V-Watch. This device enables her transformation into the superhero identity "Sexy Silvia" (localized as "Go-Go Silvia" in the English anime). Her distinct sky-blue costume features a helmet, skirted leotard, elongated ponytail, and her signature round glasses across all appearances. As Sexy Silvia, she partners directly with Joe in subsequent conflicts, notably against the Gedow army. Her combat style diverges from Joe's, utilizing twin firearms and specializing in the "Replay" VFX power. This ability replays her actions three times consecutively, multiplying damage when timed precisely and generating electrical visual effects. Her civilian appearance evolves. Initially seen in a pale blue blazer dress in the first game, later iterations show her in a pink V-neck minidress with white accessories: fingerless gloves, heeled boots, and a visible V-Watch. Sylvia's relationship with Joe develops into a battle partnership, retaining elements of romantic tension and occasional conflict. Instances occur where Joe's flirtatious behavior toward other characters provokes her reaction, minimized in the English anime adaptation. Her familial loyalty remains central, particularly her dedication to her father and her sister Goldie, who appears in alternative storylines as a captive used in sacrificial rituals. Beyond the core games, Sylvia appears in crossovers. She assists Joe during specific combat sequences in fighting games like *Tatsunoko vs. Capcom* and *Marvel vs. Capcom 3*, notably riding atop the Six Machine cannon during his "Desperado" hyper combo. She also features in broader Capcom crossovers, including the *Worlds Unite* comic storyline and the game *Wonderful 101* through the expy character "Wonder-Cheerleader" (Silvianne Lumière), who shares Sylvia's design motifs, weapon style, and narrative connections.