Seiya has the same appearance as he had when he was the Pegasus Bronze Saint, with dark brown hair and brown eyes. When he doesn't wear his Cloth, he still retains his red t-shirt, blue jeans, white shoes and red sweatbands on his arms.
As the Sagittarius Gold Saint and a much more mature Saint in age, Seiya is much more wise and calm when it comes to defending Athena and the world. He is no longer eager to fight anyone who wish to kill Athena, but only fights them in order to defend his goddess. However, during the battle against Titan, Seiya's old personality returns and he fights Titan in order to defend his loved one.
In the era of Omega, Seiya has been known by every Saint in the new generation. Seiya first appears when he saves Athena and the infant Koga from Mars, and they both disappear. Later, when Koga and his friends invade the Tower of Babel to save Aria, Seiya appears once more, saving Koga for the second time but vanish after executing a powerful Meteor Fist against Mars' Rubel Sidus Gungnir. He's seen again when he entrust Athena to the new generation of Bronze Saints. He also returns to help Koga come back to his senses by fighting the possessed Pegasus and drive Abzu out of his body, and thus, the legendary Seiya once more proves what he is willing to go through for his goddess. After a hard battle, Seiya manages to expel Abzu from Koga, and because of his severe Darkness wounds, he gives Koga his Cloth and tells him to follow Abzu and defeat him.
In Season 2, Seiya is seen holding the golden dagger Saga once tried to kill Athena with, as he had been given the order to find and kill Pallas, but he hesitates to long, and is attacked with a surprise attack by Titan, who takes her and leave, with Seiya being shameful for failing to prevent the battle that will now come between the Saints and the Pallasites. When Koga arrives to see to Athena, Seiya appears, telling Koga what the different ranks of the Saints will do (The Gold Saints protect Athena, the Silver Saints search for Pallasites, and the Bronze Saints are to inform as many Saints as possible and prepare for battle) with Koga responding that he better protect Athena or he will be mad, with Seiya saying that there is no need for Koga to tell him that, and he should just mind his mission.
Time to strike back
Seiya later arrives to defend Pallaestra against Hati and a horde of Pallasites, before deciding to lead a group of Saints to go to Pallasvelda and kill Pallas. While fighting, Seiya encounters Eden who has also become a part of the battle, and the Gold Saint reassures Eden that while he is the demigod son of Mars, it is only him alone that can chose where to go and whom to protect before leaving.
Encounter with Pallas
After sensing Pallas' Cosmo, Seiya rushes to the Bronze Saints' aid who struggle against Titan. Shooting the golden arrow, Seiya is shocked to see Titan blocking it, before Pallas sends it back, only for Koga to step between, taking the damage from the arrow, horrifying the Gold Saint.
When the Saints managed to break the Gate of Time, they found four different paths to take. Splitting up into groups of four, Seiya, Athena and the Gold Saints Fudo, Harbinger and Kiki took the path of Vanaheim, as protecting Athena was the important mission of the Gold Saints. Later, Seiya is seen completely devastated at Ikki's death before heading onward on their mission.
The unescapable fate
While the Gold Saints keep moving, encountering dozens of footsoldiers, they eventually are confronted by Paradox, who is about to kill Athena. However, the other Gold Saints watch as Integra arrives to battle her sister and in the end, defeat the evil in her.
After the battle against Paradox has ended, Gallia arrives, wounds Paradox and confronts the Gold Saints and Athena, as Paradox had lost and was of no more use. Facing the Class 1-Pallasite, Seiya's Ryu Sei Ken and Atomic Thunderbolt are both easily dodged by Gallia and she prepares to kill Seiya. However, Pallas' voice interfere, and Seiya quickly escapes Gallia who confronts Pallas about their loyalty to another god operating behind Pallas. As she moves to kill Athena, Seiya notice Paradox and Integra combining their Cosmo to attack Gallia, although it later is revealed that they combined their Cosmo to allow the other Saints to arrive. After Paradox dies, Gallia tells the Saints to follow her to a more open space where she states she will kill them all. However, Koga tells Seiya to go with Athena and the other Gold Saints and leave Gallia to them. Reluctantly, Seiya travels ahead while the Bronze Saints fend off Gallia and face her, with Athena and the Gold Saints noticing them defeating Gallia with their Omega Cosmo before moving onward where they would eventually face Hyperion.
Being greeted by the challenge of Hyperion, all the Gold Saint's attacks prove useless, and Seiya and Harbinger's Cloths are damaged in the process. Sworn to their goddess, Seiya and Shiryu try to attack Hyperion at the same time, but both are easily deflected by the Class 1-Pallasite. Sending Seiya, Harbinger and Athena ahead, Shiryu, Fudo and Kiki stay behind to face Hyperion and defeat him. The duel ends in a sad defeat as the Gold Saints use Athena Exclamation and sacrifice their lives, only managing to destroy Hyperion's sword, while Hyperion survived.
Reaching Pallas' chamber at last, Harbinger quickly charges to rid of Pallas, but Titan steps between and the two start a fierce battle. After their battle is over, Athena and Pallas finally clash in their fated encounter, which ends with Athena being victorius. Now that the goddesses' battle is over, their guardians Seiya and Titan must now finish the encounter. As Titan reveals his Genesistector, Seiya removes his scarf, evolving his Cloth into the Sagittarius God Cloth. Now being truly serious, the two men charge at each other, with maximum power. Titan seems at first to have the advantage, but Seiya reveals a little bit of his previous personality during the battle, the same personality he used to have during battle as a Bronze Saint. As both men claim that they fight because they love their goddesses, they decide to finish the fight, Seiya being able to finally give Titan a grave wound. However, before they can resume, Pallas interfere, not wanting to see Titan hurt, and she and Athena reconcile their love for each other.
The rise of Saturn
Before they can truly reunite, the rings on their arms absorbs their Cosmo and leaves them trapped. Trying to save their goddesses, Seiya and Titan furiously charge at Europa, but are easily deflected by the Class 2-Pallasite who reveals that all along he was a Class 1-Pallasite who swore allegiance to another God who had operated in the shadows. Performing the Ourobos ritual, the mighty God of Time Saturn awakens inside Subaru, horrifying Seiya, Koga and his friends.
Following Saturn, Seiya and the Omega Saints are easily defeated by the mighty God of Time. However, Seiya stands up and fight Saturn alone, as Koga and the others achieved Omega through the desire to save Subaru, and that it would be impossible for them to kill the one they sacrificed their lives for earlier. Charging at Saturn, Seiya's Cloth is shattered every time he tries, but during his final strike, he manages to get close to the god and stab him with the golden dagger, capable of slaying gods. However, Saturn easily destroys the dagger and stabs Seiya with several purple shards. Seiya tells the Omega Saints that he entrust the world to them, before a huge explosion occurs, and Seiya collapses to the ground, presumabely deceased.
Now a Gold Saint, Seiya has mastered the 7th sense and can move at the speed of light. Seiya also manages to burn his Cosmo to the limit required to awaken the Sagittarius God Cloth, allowing him to fight at the same level as Titan. During the battle against Saturn, Seiya held his own during the entire match, sacrificing the Cloth in the process. As a Gold Saint, Seiya's Cosmo is now golden-yellow instead of blue.
Pegasus Ryu Sei Ken: Seiya burns his Cosmo, and then unleashes dozens of meteors. However, when his Cosmo increase, so does the amount of punces and they also increase in speed. As a Gold Saint, the Meteor Fist is able to move at the speed of light.
Sagittarius Arrow: As the Sagittarius Gold Saint, Seiya can shoot a golden arrow from the bow that comes with the Sagittarius Gold Cloth. He tried to shoot Pallas, but the arrow was reflected by Pallas.
Atomic Thunderbolt: The legendary technique of the previus Sagittarius Gold Saint Aoiros. Similiar to the Ryu Sei Ken, Seiya unleashes dozens of golden rays at light speed to deal with his enemies. Seiya used this for the first time when he arrived to defend Pallestra after Genbu's death.
Cosmic Star Arrow: Seiya aims the Bow of Sagittarius at his opponent, focusing his cosmo at the tip of the arrow and unleashes volleys of energy. When the technique ends, Seiya draws the energy into the tip and releases the arrow with devastating force. It should be noted that the cosmo emenating from the tip of the arrow glows blue in appearance, and not golden like a normal Gold Saints cosmo until it is focused into the arrow tip. This technique was so immense in power, it was actually able to damage Titan's Genesistector, a Chronotector with the strength of 3 Gold Cloths.
Seiya wears the Sagittarius Gold Cloth which has received some changes in appearance since when Aioros wore it. It now features a long white scarf, and the wings have sharp, pointy ends. There is also a diamond at the chest, just like Koga's Pegasus Cloth.
New Gold Cloth
As Seiya is about to face Titan, he removes the scarf and his Cloth. Soaring into the heaven, the Sagittarius Cloth evolves into a New Cloth and covers Seiya's body once more. The shape of the Cloth has changed drastically from it's Clothstone form. The wings have increased in size, and also separated, instead of gathering into pointy ends. More engravements have been added on the Cloths, and it also receives diamonds on the knees, arms and on his headpiece.
- Seiya is the only Saint who burned his Cosmo to the maximum without killing himself as he burned it to fight Abzu/Koga.
- Seiya is presumably 38 years old in the era of Omega as he was 13 in the original series, and 25 years have passed since then. That would make him 39 during the battle against Pallas.
- So far, Seiya is the only Saint with a God Cloth, as Koga and the others received the Omega Cloths which may seem god-like in appearance.
- For some unexplained reason, Seiya did not wear his helmet until the second season.
- When he faces an opponent in battle, they usually call him "Golden Pegasus" or "Sagittarius".
- Until the moment where Seiya and Titan battle, Seiya has called Athena by her goddess name, but from the battle against Titan, Seiya reverted to calling Athena "Saori-san", having regained his former personality once more.