Orphaned Seiya trained in Greece under Eagle Marin, separated from his sister Seika. To find her, he returned to Japan after obtaining the Pegasus Bronze Cloth and entered the Galaxian Wars tournament. While his driving purpose remained reuniting with Seika, his focus expanded to protecting Athena as he fought alongside fellow Bronze Saints. He displays extraordinary determination, refusing surrender against impossible odds. Impulsive yet kind-hearted, he risks his life for justice and comrades. His combat relies on instinct and adaptability, overcoming stronger opponents through perseverance and tactical ingenuity. Key techniques channel his inner Cosmo energy: the Pegasus Meteor Fist unleashes rapid-fire punches, while the Pegasus Comet Fist delivers a concentrated, powerful strike. Through battles, Seiya awakened advanced Cosmo senses: - The Seventh Sense (Miraculosity) unlocked his full cosmic potential, enabling light-speed movement and energy projection. - The Eighth Sense (Afterlife) granted soul and body control within the Underworld, permitting resurrection and navigation of Hades' realm. His Pegasus Cloth evolved during critical fights, manifesting wings for flight and dimensional travel. Against deities like Hades, it transformed into a God Cloth with heightened power. Defying Athena's orders in the Hades Chapter-Sanctuary arc, Seiya intervened in Aries Mu's battle against resurrected Specters. He confronted Wyvern Rhadamanthys but faced defeat, requiring rescue by Gold Saints – highlighting his disregard for authority when protecting others. His relationship with Athena evolved from skepticism to unwavering loyalty, marked by willingness for self-sacrifice. He shares a profound bond with fellow Bronze Saints Shiryu, Hyoga, Shun, and Ikki, frequently battling divine threats alongside them.