Zeke Bana commands the Gaist Crusher Garrison (GCG) battle squad, leading specialized combat units against the metallic lifeforms called Gaist. Known among teammates as "Captain Bana," he coordinates and directs missions targeting these threats.

He relies on an artificial Gaist Gear for combat, contrasting with the organic Gaimetal-based armors of primary Gaist Crushers. This synthetic armor amplifies his peak physical conditioning and mental resilience during Gaist engagements. Though the technology’s origins remain undisclosed, its artificial nature distinguishes it from standard GCG equipment.

Within the GCG hierarchy, Captain Bana collaborates with Director Rock Vulcan and operator Sakura Sango. During field operations—especially training scenarios—he delivers real-time tactical oversight and combat guidance to recruits like Rekka Shirogane, ensuring mission coordination and strategic support.