Captain Avatar, originally Admiral Jūzō Okita in Japanese media, commands as a central military leader for the Earth Defense Forces against the Comet Empire. He leads from Earth's flagship Andromeda during the invasion, coordinating planetary defenses against superior enemy strength. His battlefield tactics involve executing flanking maneuvers near Saturn's moon Hyperion and ordering the Earth fleet to charge their Wave-Motion Guns despite exceeding effective range.

His leadership demands Earth's survival as the paramount objective. This compels him to insist subordinate commanders safeguard their flagships above all else during retreats, contrasting with original Japanese counterparts motivated by personal honor. During the Saturn engagement, Avatar displays tactical adaptability, luring the Comet Empire fleet into the planet's ice rings. This maneuver exploits the environment to disable their Magna-Flame Gun and create a crucial opening for counterattack.

Avatar sustains a mentor relationship with Derek Wildstar, shadowed by the loss of Wildstar's brother Alex under his command during an earlier Pluto battle. This bond reflects the weight of responsibility he carries for fallen subordinates. His final command coordinates a simultaneous Wave-Motion Gun barrage against the Comet Empire after the Argo's incapacitation. When this fails to destroy the target, Avatar transmits vital tactical intelligence regarding the enemy's structural weakness to Wildstar. His death occurs off-screen during this transmission, marked by the abrupt severing of communication amidst an explosion on the Andromeda.

The character's portrayal incorporates the mortality inherent in wartime leadership, signaled by his visibly declining health throughout the series. His on-screen death represented a narrative rarity in its contemporary animated context.