Agito Makishima, also known as Guyver III, carries a past defined by tragedy and fierce ambition. His uncle Genzo Makishima deliberately bankrupted his parents' company, driving them to suicide. Genzo adopted Agito but treated him only as a tool, teaching him survival depended on making himself indispensable. This harsh upbringing unfolded under the shadow of Genzo's Max Pharmaceuticals, later consumed by the secretive organization Chronos. Within Chronos, Agito gained extensive knowledge of their operations, including Zoanoid bio-weapons and the Guyver Units—extraterrestrial bio-armor systems. He orchestrated the theft of three Guyver Units by manipulating a test-type Zoanoid, though the units scattered during the escape. While Sho Fukamachi accidentally bonded with one unit (Guyver I) and Chronos recovered another (used by Oswald Lisker, Guyver II), Agito secured the third unit for himself. He activated it secretly, becoming Guyver III while maintaining his cover inside Chronos. Agito operates with cold pragmatism and an unrelenting drive for power. He views emotions as weaknesses and allies as pawns, demonstrated by his manipulation of Sho and Mizuki Segawa. Initially focused on revenge against Genzo, his ambition expanded to usurping Chronos's global authority. Adopting the codename "Zeus" to signify his intent to overthrow the organization as Zeus overthrew Cronus, he formed the resistance group "Zeus' Thunderbolts" after Chronos's global takeover (X-Day). His actions showcase strategic ruthlessness. He allowed Sho to die during a battle with Genzo (as the Zoanoid Enzyme) to study Guyver regeneration. He later destroyed Chronos's Japan branch and confronted operatives like Richard Guyot. Despite temporary alliances with Sho, Agito consistently prioritized his own agenda, including betraying Sho to seize the powerful "Guyver Gigantic" armor. He temporarily controlled this amplified form (designated Gigantic Dark) through sheer willpower, though Sho ultimately reclaimed it. Agito survived the destruction of the Creator spacecraft at Relic's Point, awakening in Canada. Discovering Sho undergoing metamorphosis within a chrysalis, he abandoned him due to approaching Chronos forces. He then mobilized "Zeus' Thunderbolts" to conduct guerrilla strikes against Chronos's new world order, relying on his Guyver abilities to counter Zoanoid threats. As Guyver III, Agito possesses standard Guyver abilities: enhanced strength, speed, durability, regeneration (including full reconstruction from the Control Medal), flight via a gravity-control orb, head-mounted lasers, and high-frequency elbow blades. His armor features twin blades per arm, distinguishing it from Sho's single blades. Key weapons include the chest-fired "Mega Smasher" particle beam and its amplified "Giga Smasher" variant. The gravity orb enables offensive "Pressure Cannon" attacks and defensive barriers. His Gigantic Dark form significantly amplified these powers but remained dependent on his willpower for control. His development shows subtle shifts. Early ruthlessness—such as disregarding collateral damage—persisted through conflicts like the Battle of Yokohama. However, his defeat by Sho in the Gigantic armor and subsequent wilderness survival hinted at potential introspection. Later actions suggested a more cooperative, though still strategically self-interested, approach to confronting Chronos.