Vooren Grantz, alias Warren Grantz, is a steadfast officer in the Imperial 203rd Aerial Mage Battalion under Tanya Degurechaff’s command, distinguished by short blonde hair, emerald eyes, and military or combat attire. His background shifts across adaptations: the light novel positions him as a supplementary mage from the Officer Cadet School who survives Operation Revolving Door to remain with the 203rd; the anime portrays his training in the V601 unit, subsequent enlistment in the battalion, and rescue from a crash in Attack Plan 177; the manga details his recruitment after a night raid mission, where his magical prowess secures him a permanent role as a replacement. Crossover media briefly feature him in a school setting, volunteering to aid a classmate’s ambiguous talent show request. His military rank alternates between Second and First Lieutenant depending on the source. Personal elements include a younger sister, Ursula, subtle romantic undertones toward a comrade, and a harrowing training incident where Tanya saves him from avalanche-induced suffocation. His unwavering loyalty and disciplined adherence to duty persist uniformly across all narratives, cementing his role as a reliable, if underdeveloped, supporting figure.