When Aiolos was 14 years old, he and fellow Gold Saint Gemini Saga were summoned to Pope Shion's throne room for an audience. There, the Grand Pope revealed that their goddess had reincarnated once again in the form of an infant, signaling the Sanctuary must prepare for impending wars. As Shion was aging, he decided it was time to appoint one of the twelve Gold Saints as his successor. At the time, most Gold Saints were still too young; only Gemini Saga and Sagittarius Aiolos were considered qualified. The Pope eventually chose Aiolos as the new Pope and asked Saga to serve as an assistant to the Sagittarius Saint.
Saga, consumed by his evil side, became jealous that he was not chosen, especially since he believed himself superior to Aiolos in power and wisdom. Saga confronted Shion about his decision and killed him. Disguising himself as the Grand Pope, Saga went to kill the infant Athena. Just before Saga could strike the baby with a golden dagger, Aiolos appeared and halted the blade. The Sagittarius berated the man he thought was the Pope but was quickly shoved aside. After a brief struggle, Aiolos sent Saga flying into a wall, knocking off his headdress and mask. Upon seeing Saga's face and realizing he had killed the Grand Pope, Aiolos immediately took the infant Athena and fled from the Sanctuary.
Disguised as the Pope once more, Saga sounded the alarm and sent guards after the saint. He officially branded Aiolos as a "traitor." Aiolos was eventually found by Capricorn Shura and managed to escape but was severely injured. As he was dying, Aiolos encountered Mitsumasa Kido, who was touring Greece at the time. Aiolos begged Kido to become Athena's new guardian and explained the events at the Sanctuary. Kido learned about Athena's Saints and their Cloths. Entrusting Kido with Athena and his own Sagittarius Gold Cloth, Aiolos succumbed to his injuries. It is unknown where exactly Aiolos died and was buried, as the location is omitted in the series.
After his death, Aiolos' spirit provided assistance to Athena and her Saints. He aided Seiya in battles by lending him the Sagittarius Gold Cloth multiple times and appeared to his brother Aiolia during a fight with Seiya to demand proof of Saori's identity as Athena. When the Bronze Saints reached the Temple of Sagittarius, the Sagittarius Cloth moved on its own and fired its golden arrow into a wall, revealing Aiolos' final message: "To you young boys who have reached this temple, know that I entrust Athena's life in your hands. Aiolos." It is likely that Aiolos foresaw new Saints would one day fight for Athena.
When Athena's Saints fought against Hades' spectres, all the Gold Saints, both dead and alive, gathered to break the Wailing Wall. Only sunlight could destroy the wall, and each Gold Cloth contained solar energy. Gathering all twelve cloths provided enough light to damage the wall. Aiolos guided all twelve Gold Saints' attacks into one, striking the wall. Once the mission was completed, Aiolos and the other Gold Saints dissipated, leaving only their cloths behind.
Although Aiolos' moves were not shown in the original manga, two techniques are attributed to him in other mediums: Atomic Thunderbolt from the anime and Infinity Break from Episode G. Atomic Thunderbolt involves shooting massive energy balls with electric charge, while Infinity Break allows Aiolos to shoot infinite light darts that pierce anything upon contact.
Aiolos' Sagittarius Cloth is armed with a bow and a golden arrow, often depicted as the main weapon in the series. The golden arrow can concentrate the Cosmos of those surrounding it if they wish.
Even though most fans recognize his name as Aiolos, Masami Kurumada intended to name him Aioros, a Japanization of the Greek god of winds, Aiolos. This is confirmed in vol.11 of Kurumada's manga, where Aioros' name is spelled using Greek letters. Some attribute the discrepancy to the fact that in Japanese, the letter "L" is replaced by "R" in foreign words. The fandom is mostly familiar with the "Greek" spelling, Aiolos, though in some languages, like the Latin-American Spanish dub, "Aioros" is used.
As revealed by Masami Kurumada in vol.12 of his manga, Aioros became a Gold Saint at an early age, already granted the status and the Sagittarius Gold Cloth before turning 14.
