Bizon Gerafil is a twenty-year-old officer who holds the rank of First Lieutenant, Junior Grade, in the Zogilian Republic's military, where he serves as a frontline commander and pilot of the Nebiros Valiancer. Coming from a distinguished family, he initially appears as an upright soldier who possesses a calm and composed demeanor. His tactical abilities and piloting skills are highly regarded, earning him the trust and respect of his superior officers, such as Lieutenant Colonel Alfred Gallant. On the battlefield, he leads his unit with confidence and a strategic mind, demonstrating genuine concern for the well-being of his comrades.

However, Bizon's character is profoundly shaped by his relationship with his childhood friend and fellow officer, Hina Yumihara. He holds deep romantic feelings for her, but this love is coupled with a strong and obsessive possessiveness. When the protagonist Aoba Watase appears and begins to form a connection with Hina, Bizon perceives him as a threat and an enemy who has bewitched her. This event triggers a gradual but complete shift in his personality, transforming his initial professionalism into an extreme and irrational hatred directed solely at Aoba. His calm judgment becomes clouded by jealousy, leading him to act on impulse and aggression whenever Hina is involved.

Driven by the desire to become a pilot worthy of being Hina's partner in the Coupling System, Bizon willingly subjects himself to dangerous artificial enhancements. His natural aptitude for Coupling is very low, but he becomes a test subject for a process that forcibly raises his compatibility to an operational, though still imperfect, level. This desperation highlights that his core motivation is not loyalty to the Zogilian cause, but an all-consuming need to claim Hina for himself and eliminate his rival, Aoba.

Bizon's role in the story is that of the primary antagonist and a dark mirror to the series' themes of partnership. His hatred for Aoba becomes the engine for a critical time paradox, as his actions are directly responsible for the repeated cycles of time travel that form the backbone of the narrative's conflict. His obsession is so potent that after being pulled into a dimensional rift, he is transported back in time. Rather than seeking redemption, he adopts the alias Evgeni Kedar and spends seventy years infiltrating and seizing control of the Zogilian government, establishing a dictatorship solely to exact his revenge on Aoba.

Over the course of the story, Bizon undergoes a profound and tragic descent. The once-promising and honorable officer is reduced to a vengeful and unstable man whose sanity deteriorates further with each passing year. By the time he re-emerges as the elderly chairman of Zogilia, his hatred has calcified into a single-minded madness. He becomes willing to sacrifice anyone, including his own allies and subordinates, and even contemplates the destruction of Earth itself to achieve his vengeance. In his final confrontation, even after learning the full scope of the time loop and his role within it, he is unable to let go of his resentment, ultimately dying bitter and defeated.

As a pilot, Bizon is exceptionally skilled and commands several notable machines throughout his career. He first pilots the Nebiros, a versatile unit designed for a variety of combat roles. To pursue Hina, he later transfers to a prototype Coupling Valiancer called the Nergal. His most formidable machine is a colossal, custom-built Coupling unit designed by Doctor Hahn. This unique Valiancer possesses a virtual Coupling System that allows it to operate at full power with a single pilot by creating a simulated partner personality, granting him enormous firepower and armor.