Billy Glardle is a Zeon ace pilot operating within the shadowy remnants of the Principality of Zeon forces. He is tormented by persistent nightmares stemming from the fate of his former home colony, Mahal. During the One Year War (U.C. 0079), Zeon military forces repurposed Mahal into a devastating colony laser, an event that continues to inflict deep psychological scars. Following the war's end, Billy Glardle engaged in clandestine cooperation with Earth Federation officers Jamitov Hyman and Bask Om. His role involved conducting espionage against the Delaz Fleet during the critical events of Operation Stardust in U.C. 0083.