Vivian Medlock commands the Deague Empire warship Kunrun, holding a respected military position while relentlessly pursuing greater influence and status. She possesses purple hair, green eyes, and a distinctive birthmark. Her pivotal role commences upon meeting Ralph Werec, a Galactic Union defector offering aid to Deague. Ralph’s proposal enables Vivian to target a Union vessel transporting an Emilies specimen—valuable alien technology promising military supremacy—to elevate her standing.

Though typically authoritative and self-assured, Vivian grows emotionally compromised by her bond with Ralph. She dismisses warnings from Lieutenant Colonel Barrow about Ralph’s hidden Union agenda and ulterior motives, trusting him with near-unquestioning obedience while maintaining the illusion of control. This dynamic drives her to defy Deague’s high command in favor of Ralph’s guidance.

Vivian’s ambition and impaired judgment culminate in Ralph’s betrayal. During the Kunrun’s final confrontation with the Union ship Libertad, Ralph traps Vivian helplessly in her shower quarters. He seizes the Kunrun, initiates its self-destruct sequence, and rams it into the Libertad. This eradicates Vivian and her crew, fulfilling Ralph’s genocidal scheme to eliminate humanity after exploiting both Deague and her ambitions.