Kanon des Gémeaux, also known as Gemini Kanon, is the younger twin brother of Gemini Saga. Initially ambitious and treacherous, he believed their potent abilities were divine gifts meant for exploitation. He persuaded Saga to assassinate Pope Shion and the infant Athena to seize control of Sanctuary, leading Saga to imprison him at Cape Sounion. During his confinement, rising waters repeatedly threatened to drown him, but an unknown gentle Cosmo—later revealed as Athena's—intervened each time to save him. Discovering Poseidon's trident sealed within the cave, Kanon freed it, transporting himself to the underwater Sanctuary of Poseidon. He awakened the sea god's spirit within Julian Solo and assumed the identity of the Sea Dragon General, intending to manipulate Poseidon's army to conquer land and sea. He orchestrated Athena's abduction to lure Sanctuary's forces into a trap, though the Bronze Saints thwarted the plan. Confronting Phoenix Ikki revealed Athena as the source of the Cosmo that saved him, planting the first seeds of his redemption. After Saga's death, Kanon sought atonement. Athena permitted him to inherit the Gemini Gold Cloth. To prove his loyalty, he endured a brutal assault by Scorpio Milo without retaliation, culminating in Milo delivering a non-lethal strike that halted the bleeding, earning Kanon the trust of the remaining Gold Saints. As the new guardian of the Gemini Temple, he used his Genrou Ken technique to create illusions delaying Hades' forces, including his deceased brother and other resurrected Gold Saints. When Hades' Specters invaded Sanctuary, Kanon joined the mission to the Underworld. There, he overpowered Wyvern Rhadamanthys, one of Hades' judges, until interrupted by additional Specters. In a final sacrifice, Kanon removed his Gold Cloth—sending it to aid his allies—and immobilized Rhadamanthys before detonating his Cosmo, killing both. His techniques include Galaxian Explosion, a destructive energy wave; Genrou Ken, an illusion-based fist manipulating perceptions without requiring the target to kill; and Astral Projection, allowing remote control of his Cloth. Physically resembling his brother Saga, Kanon has blue hair and a muscular build, with slightly shorter hair in some depictions. His character arc transitioned from villainy to redemption, culminating in a heroic sacrifice affirming his allegiance to Athena.