Kanon Seadragon is a major character from the anime and manga series Saint Seiya, created by Masami Kurumada. He is the twin brother of Gemini Saga and initially appears as an antagonist, manipulating events as the Sea Dragon General under Poseidon. Kanon is cunning and ambitious, but he eventually seeks redemption and fights alongside the Saints. His transformation from villain to ally is a key element in the Poseidon and Hades arcs, making him a complex and memorable figure in the series.