However, Saga also has an evil side, which serves as the main antagonist of the Sanctuary Arc, as he is the man responsible for the Pope's murder, ruling in his stead in order to kill Athena.
But that attempt is prevented by Aioros who sacrifice himself to rescue his goddess from certain death.
Good: He has blue hair and blue eyes. Although barely visible, he seems to wear a black outfit while wearing his Cloth, but it's hard to tell as Saga's Cloth is the only one to cover almost all his body.
Evil: When he is taken over by his evil personality, he is seen with blood-red eyes, white hair and a menacing look.
Good: Saga is a very calm and mature saint, being one of the oldest Gold Saints, at the age of 28. He is very regretful when Seiya reaches his chambers, and all he can say is that he can't save Athena, even shedding tears. However, even after his demise, he gives Seiya advice when it is needed.
Evil: Saga's evil personality shows a more menacing and violent Gold Saint, willing to kill his own goddess and rule the Earth as a god. He shows no mercy, and thinks it's not in anyone's right to deny him his goals to rule the Earth and kill Athena.
The Pope's Chambers
At the time where all the Gold Saints have been defeated, Seiya finally arrives at the Pope's Chambers where Saga removes his mask and his face is shown for the first time. He exclaims that he cannot save Athena, but behind him is a statue of her, where her shield is. Stating that the shield will save Athena, Saga tells Seiya to hurry up, as he suddenly starts struggling with his mind. As Seiya start walking, he is suddenly told to hold it, and Saga's hair change color before he strikes the Bronze Saint with a lightspeed fist.
As Saga reveals himself as the Gemini Gold Saint, the two Saints engage in a brutal fight, with Saga leaving Seiya deprived of all his senses. Fortunately, Ikki arrives to save his friend, and fights with Saga as Seiya struggles to reach the statue of Athena. Saga quickly use his "Another Dimension" technique to get rid of Ikki, but he returns and manages to knock Saga down. During the end of their battle, Saga notices the damage in the chamber, and use that to his advantage in order to take down Ikki. With the Phoenix out of the way, Saga rushes after Seiya in order to prevent him from reaching the shield.
As he catches up, he notice Seiya standing next to the statue with the shield. Quickly, Saga strikes Seiya in the chest, knocking him unconscious. However, he is too late, as he suddenly notice Athena's Cosmo, meaning that Seiya managed to remove the arrow before falling. Furious at having failed to kill Athena, Saga launches dozens of lightspeed blows at Seiya, swearing to slowly tear him apart, damaging Seiya's Cloth even more in the process. As he is about to deliver the killing blow, he is interrupted by Ikki who once more tries to resume his fight with the Gold Saint. Easily dodging Ikki's "Ho Yoku Tensho", Saga remove his senses and shatters his Bronze Cloth. As he tries to kill Ikki, he is once again interrupted, this time by Athena accompanied by Shiryu, Hyoga, Shun, the remaining Gold Saints as well as the Bronze Saints from the Galaxian Wars tournament.
Refusing to let their friends die, Shiryu, Hyoga and Shun burn their Cosmo to the maximum in order to take down Saga, but the Gold Saint easily reflects the techniques, knocking them unconscious as well. However, Saga turns around to see Seiya once more struggling to get up to his feet. Shocked to see that Seiya is still alive, he finds himself surrounded by the five Bronze Saints who all burn their Cosmo to the maximum, before Seiya gathers all the Cosmo from his friends and executes a final "Pegasus Ryu Sei Ken" against Saga, which sends the Gold Saint flying high up into the sky.
As Saga lands once again on the ground, seemingly unharmed, he prepares to kill Athena, but notice that the evil side within him was actually destroyed by Seiya's last technique as all the Bronze Saints reached their 7th sense before sending it to Seiya. As the Gold Cloth abandons him, Saga launches himself at Athena, commiting suicide at her staff. As he lies in Athena's arms wounded, his hair color reverts to its original blue color, and he apologize to Seiya and his friends before he dies.
Saga makes a minor appearance when he encourages Seiya to stand up once more and don't give up during his final battle against Hilda.
Once more, Saga makes an appearance, during where Ikki mistakenly thinks that Saga is still alive when he is attacked by a powerful technique and Cosmo which could only belong to Saga. It is revealed that it's his twin brother Kanon who is the true evil among the two twins, and the one who triggered Saga's evil personality during his imprisonment at Cape Sunion.
During an illusion from Ikki, the two brothers, wearing their respective armors (Kanon wearing his Scale, Saga wearing his Gold Cloth) have another encounter, where Kanon suddenly is vaporized, due to the effects of the "Gen Ma Ken".
Wall of Grief
Saga is resurrected and rejoins his fellow Gold Saint companions, informing Dohko that they must destroy the Wall of Grief, gathering his Cosmo into Aioros' arrow. The impact from their Cosmo is enough to destroy the wall, but the Gold Saints are unable to survive the blast, and only their Gold Cloths are left behind.
Being a Gold Saint, Saga is able to move at the speed of light, launching attacks at 300 000 km/s, as well as deflect the attacks from other Saints of either the same rank or lower with minimal effort.
He is also able to disable an opponent's senses, leaving them totally paralyzed.
Another ability Saga has, is the power to control other humans and turn them into some kind of demon who will only wake up when their target is dead. Saga's Cosmo has a golden aura like his fellow Gold Saint companions.
Saga is considered the strongest Gold Saint, with other powerful Gold Saints such as Mu and even Shaka are shown to slightly fear Saga's tremendous power and Cosmo.
Another Dimension: Saga creates a large rift to the infinite space, sending his opponents stranded there for all eternity. The true power has never been seen, as Shun manage to withstand that blow thanks to his chains and Ikki's intervention for a brief moment, and Seiya survives the attack as Saga was then struggling between his good and evil personalities.
Gen Ro Mao Ken: Saga launches a straight line, similar to Ikki's "Phoenix Gen Ma Ken", allowing him to control his opponents. As he exclaims, they will feel a little pain while under control from that technique. He has used it twice: on Crystal Saint in order to have him kill Hyoga, and on Aioria in order to have him kill the Bronze Saints as they arrive at the House of Leo.
Saga wears the Gemini Gold Cloth, which covers almost the entire body, even covering a little more of the waist than any other Gold Cloth, as the outfit he wears is barely visible. Draped around his shoulders is a white and blue cape. The Gold Cloth's mask is one of the most noticeable things, as it has one "good" face on one side, and an "evil" face on the other side, indicating the inevitable fate of the Gemini Gold Saint.