Warren Grantz, occasionally translated as Vooren Grantz, is a Second Lieutenant in the 203rd Aerial Mage Battalion led by Tanya von Degurechaff. A young man with short blonde hair and green eyes, he operates as a core member of the elite unit, engaging in high-stakes combat across pivotal conflicts such as the brutal urban warfare in Arene and the swift, devastating strikes in Dacia. The battalion’s reputation for circumventing conventional warfare rules through tactics like nighttime raids and exploiting legal technicalities for bombardments is bolstered by Grantz’s steadfast participation.

As one of the original survivors of the 203rd, his unwavering loyalty to Tanya anchors his role, though moments of levity emerge—such as stress-induced slips where he addresses her with familial terms like "mom"—hinting at the unit’s nuanced dynamic. During the Eastern Front campaign against the Russy Federation, Grantz contributes to combined military-propaganda operations, executing strategic strikes while participating in staged recordings meant to bolster wartime morale. His individual actions remain entwined with the battalion’s collective precision, operating under Tanya’s exacting command hierarchy without deviation. No personal history or expanded character arcs beyond documented military engagements are detailed.