Leo Aiolia (獅子座のアイオリア Reo no Aioria?) is the first Gold Saint introduced by Masami Kurumada in his manga, along with Saga disguised as the Pope, in vol.1, although their rank was revealed until later volumes. In his first appearance, Aiolia was present during the moment Pegasus Seiya was granted the Pegasus Bronze Cloth and the status of Athena's Saint. Aiolia is shown as a reference in the Sanctuary due to his righteousness and strength. He is the young brother of Sagittarius Aiolos, considered a traitor that attempted to kill Athena when she was still a baby. Due to this, Aiolia works hard to prove his loyalty to the goddess and erase the shame his brother's actions bestwon upon them. Even during the time Aiolia thought Aiolos was a traitor, he showed immense respect toward his memory. Aiolia is impetuous and has a hot spirit that incites him to action. More than once, this create some conflicts between him and the calm Aries Mu. Through the story, it is hinted that he and Virgo Shaka are close friends. Aiolia is named after the mythical island Aiolia or Aeolia, residence of Aiolos, the god of winds.
Aiolia had mastered the 7th sense, so he is able to move at the speed of the light. It is also hinted that he achieved the 8th sense so he could awaken in Cocytos. Throughout the series, Aiolia has shown telekinetic abilities and, in the anime version, healing power through the use of his Cosmo energy.
In a fight Aiolia normally uses two techniques made of electricity. With his Lightning Bolt (ライトニングボルト Raitoningu boruto?): Aiolia blasts the opponent with a massive energy capsule and with his Lightning Plasma (ライトニングプラズマ Raitoningu Purazuma?) (Aiolia's signature technique), Aiolia generates multiple small weak plasma energy which travel at the speed of light. If he is using the maximum power of his cosmos, the technique allows Aiolia to fire 100 billion rounds of plasma per second at his opponents. From the view of his opponent, he would see himself trapped in a net formed from rays of light.
In Saint Seiya Episode G Aiolia comments that the Lightning Bolt is a stronger attack than the Lightning Plasma because the first is single hit while the second are multiple hits. Episode G also shows two new techniques that Aiolia has never used in the original series. With the Lightning Fang (ライトニングファング Raitoningu Fangu?) Aiolia sends his Cosmo energy into the ground, then it erupts as many pillars of electricity. This technique can be used to defend himself against incoming attacks, to attack his enemies or to paralyze targets.
Aiolia's strongest attack in Episode G is the Photon Burst (フォトンバースト Foton Bāsuto?). Although immensely strong, it demands a high amount of time to be prepared and leave Aiolia exhausted after used. It consists of three movements: Invoke, when Aiolia expels his Cosmo energy into the area creating many orbs of photon; Drive, when the photons are directed at his enemy, entering its body through the skin; and Burst, when the photons explode, destroying the target inside out. Since it attacks the enemy from the inside, it negates the hardness of armors.