Nikolai Avtotor, a middle-aged human male, operates under the Post-war Reconstruction Implementation Agency, Kleeman. As second-in-command of the mercenary Gillette Corps, he relentlessly pursues Chaika Trabant to obstruct her collection of Emperor Arthur Gaz's remains, seeking to prevent renewed conflict.

He wields a Great Sword Comblade as his primary weapon, embodying his frontline combat role. His mercenary background grants him considerable strength and combat proficiency, though precise fighting techniques remain unspecified.

The surname Autotor—alternatively spelled Avtotor—stems from the Avtotor automobile factory, merging "auto" with the German word "tor" meaning "gate." This naming convention reflects the series' recurring automotive motif.

Documented appearances occur in the light novels' first volume, the manga's third chapter, and the anime's debut episode.