General Colbert is a high-ranking officer within the Allied Defense Force, holding the rank of brigadier general or rear admiral. He is a career military man through and through, characterized by his bald head and an intimidating, imposing presence. While he possesses a strong will to annihilate the alien Radam, his primary driving force is not a selfless sense of duty to protect humanity but a deep-seated and egotistical desire for personal glory. He is ultimately obsessed with becoming the hero who saves humanity, a goal that fuels many of his decisions throughout the story.

Colbert is best described as an ambitious and unscrupulous individual. He is willing to do anything to achieve his goals, showing a remarkable lack of concern for the sacrifices his plans would demand from others. This single-minded pursuit of becoming a celebrated war hero makes him a dangerously volatile figure, even to his own side. He is not, however, incompetent; he demonstrates strategic ability by devising operations like "Operation Sunset" and championing the development of terrestrial weapons systems, including the Sol Tekkaman units and Fermion weaponry. Yet, his successes only serve to inflate his arrogance and reinforce his belief in his own heroic destiny.

His most significant relationship is with his former classmate from the military academy, Heinrich von Freeman, the leader of the independent Space Knights. Colbert harbors an intense, bitter rivalry and jealousy towards Freeman, who operates outside the standard military chain of command. This resentment causes Colbert to view the Space Knights not as allies but as obstacles. He is perpetually antagonistic towards them, issuing demands, performing sabotage, and attempting to absorb their most powerful asset, the Tekkaman Blade, into his own forces. His obsession with Blade is total; he is determined to either control the young warrior and his world-shaking power or, failing that, eliminate him as a threat to his own ambitions.

Colbert's role in the story evolves from that of a difficult and obstructive ally to a full-blown antagonist. Initially, he schemes to have the Space Knights hand over D-Boy, the human identity of Tekkaman Blade. When this fails, he dispatches a spy, Balzac Asimov, to steal research data, which leads to the creation of the Earth-made Sol Tekkaman suits. However, the disastrous failure of the operation to retake the Orbital Ring, where the prototype Sol Tekkaman is nearly destroyed, pushes Colbert over the edge. Cornered and humiliated, he devises a final, catastrophic plan to fire a super-polymer Fermion missile directly at the Orbital Ring, mistakenly believing it to be the Radam's main base. When his subordinates and the Space Knights try to stop him, pointing out that the attack would instead cause the Ring to collapse onto Earth, killing billions, he dismisses the loss of life as insignificant. His obsession deludes him into believing that this act of mass destruction is his moment to shine as humanity's savior. In his final moments, Colbert is a man consumed by madness, laughing with a crazed conviction even as his plan is thwarted. The missile is destroyed by Blade, and the resulting blast engulfs Colbert's base, bringing about his death.

While General Colbert possesses no superhuman abilities of his own, his military authority is his most potent weapon. He commands significant forces and resources, which he leverages to apply pressure, conduct espionage, and spearhead weapons development. His true impact comes from his political and strategic influence within the Earth’s military hierarchy, which he uses to push humanity to the brink of a self-inflicted disaster.