Hades

is a mythological deity and serves as the primary antagonist in the last story arc of ''Saint Seiya. His name means "the unseen". ''His pet is the three-headed dog Cerberus.

In the story, Hades is the ruler of the Underworld and old enemy of Athena. He wishes to wipe out humanity, turning the Earth into a desolate wasteland. Orphée described Hades as a prudent deity. He despises the human beings, who are each time more ungrateful towards the gods.

Avatars
In Saint Seiya, as in the Greek mythology, Hades is the Underworld god, and as such, incarnates into a human being. Every 243 years Hades can enter the world of humans, and fight against Athena for control over the world. However it is said that Hades is too fond of his own body which was born by Cronus and Rhea. He cares so much of it that he keeps it locked in a chamber in Elysion so it doesn't get damaged, only to start using it when he has taken control over the world. To fight the sacred wars against Athena, Hades has to take control of the purest human being born at the time of his incarnation. During the previous Holy War in 1747 his avatar was a boy named Alone, and now more recently it was Andromeda Shun.

The Greatest Eclipse
After the Specters were ordered back to the Underworld and Pandora's Castle collapsed, Hades waited in Judeca, knowing that his new avatar Shun would come. After Lyra Orphée was killed by Wyvern Rhadamanthys during a failed assassination of Hades, Shun became possessed and Seiya was thrown into Cocytus. Meanwhile, Ikki defeats Garuda Aiacos in the fifth prison. Hades senses his cosmo and orders Pandora to bring the individual. Ikki is warped to Judeca. There, he fights against Pandora and remembers he had already seen her once. Pandora tells him that the "Yours Ever" pendant she gave Shun years ago was the chain that tied him to Hades. Shun takes a brief possession of his own body and tells Ikki to kill him in order to destroy Hades and stop the Greatest Eclipse, which will cause the alignment of nine planets including the planet Pluto itself and will darken the earth. However, Ikki wasn't able to do it, and was thrown into Cocytus by Harpy Valentine. Later, Athena and Virgo Shaka arrived; Athena asked him for a bargain: At the cost of her life, the Greatest Eclipse should stop. However, Athena's blood expels Hades from Shun's body. Enraged, Hades pulls Athena with him to Elysium.

Elysion
Seiya, Shun, Shiryu, Hyoga and Ikki reach Elysium. There, they fight Thanatos and Hypnos. However, after the twins are defeated, Hades is a prudent deity but he is still lured by Athena to wake up in his own body. He fights the five Saints at once, receiving little damage to his God Cloth. When Seiya asks why Hades' eyes are so sad, Hades sees Tenma in Seiya. Athena joins the battle and duels Hades. Seiya, trying to protect her, is mortally wounded by Hades' sword, and fell in coma in front of Athena and his friends. Shun, Shiryu, Hyoga and Ikki concentrate their cosmos into Athena's Victory Staff. She throws her weapon into Hades and destory's his body.

In the newest Manga comic book series. Athena and Shun travel back in time to save Saiya. From Hades curse. Athena was turn into a baby. She later gets killed. Shun talks to her soul in the realm of the dead. Athena tells Shun there is still time to save Seiya. Which must mean that Shun will in the latest saga battle Hades. In the past to save Athena and Saiya's souls from Hades.

The Lost Canvas
Main Article: Hades (TLC)

In the 18th century, the avatar of Hades, Alone (アローン, Arōn), was a close friend of the Pegasus Saint of that era (Tenma). His soul was born in the Lost Canvas era from Pandora's mother. He is a young painter and also Hades' chosen body for his incarnation in the 18th century, as he possesses the purest soul in that era. He is an Italian orphan raised alongside Sasha and Pegasus Tenma, who later become arch-enemies. Alone believes that everybody has a good side and disapproves the use of violence. At first he rejects his fate as the god of the Underworld, but is later convinced by Hypnos, and sealed by Pandora's kiss. Before Tenma leaves for the Sanctuary, they make a promise that, while Tenma tries to become a Saint of Athena, Alone too must try to become a good artist so that he can finish the painting of Tenma when they once again reunite.

During the next two years, his personality undergoes a drastic change after realizing everything he painted dies. Convinced by Hypnos, he starts to believe that death is the ultimate salvation. And to bring salvation to the entire world, Alone starts to paint the "Lost Canvas", a painting of the Earth viewed from space, so that after he finishes it, the entire world will die.

It has been implied that Alone is not yet totally possessed by Hades as Alone drew in the Lost Canvas an image of Tenma, Sasha and himself in their childhood. After seeing this, Pandora uses a seal given by Hypnos and Thanatos to seal him in a dimensional isolation, in hope that he will continue painting the Lost Canvas without distractions, and to keep him away from the grasp of anyone from his childhood life.

Alone confesses to Pandora that he was never possessed by Hades and that he truly believes in death as the ultimate salvation, hence he inflicts it on those he holds dear, to spare them the suffering of pain, wars and poverty, and to achieve such goals, he will use all the power of the god of the Underworld. Alone states that once the Stellar Clock (星時計, Hoshidokei), which is visible in the nightsky, completes one cycle, the Lost Canvas will be finished, bringing death to the entire world.

Abilities and Attributes
Hades is one of the most powerful deities in the Saint Seiya Universe, being Zeus' brother. As the God of the Underworld, Hades can allow his specters to travel from the Underworld to the Living World, also, he can resurrect any living being at will (as he did with his deceased Specters, and Cerberus during The Lost Canvas series).

As usual, he uses an avatar when he returns to Earth, but it must be the purest soul on earth. Hades stores his mythological body and his Surplice in Elysion, and is kept in a marble tomb while defended by the minor deities Thanatos and Hypnos.

When the Bronze Saints attack his tomb, he returns into his body. Being a deity he is a possessor of the Big Will (Divine Cosmo) but, unlike his brother Poseidon in the Saint Seiya series, he could use all the power of his Divine Cosmo.

In myth, Hades owned an Invisible Hat. Kurumada changed it from hat to sword. Or perhaps the helmet of Hades' Cloth was the Invisible Hat itself. In the story, the Invisible Sword possesses non-life aura that hurts souls directly. In real life it may be called Red-Overlay Aura(not red aura) that annoys some humans.

Trivia

 * In addition to being her archenemy, Hades is also Athena's uncle. In classical mythology, there was no ill will between Athena and Hades, and interaction between them is only depicted once, in a handful of paintings depicting the Rape of Persephone, Hades's wife. In the paintings, as Hades kidnaps Persephone, Athena and Artemis try to save her, but Hades proves too fast for them to catch.
 * The original description of Hades shows him as something of a neutral figure; he is a stern and immovable god, but he is just and had no interest in the human world, although he became furious with those who attempted to escape the Underworld against his wishes. In contrast, the Hades of Saint Seiya is a lot more antagonistic and aggressive towards human beings.
 * Hades' attitude regarding humans is mirrored, interestingly, in the character of his wife, Persephone, in the video game God of War: Chains of Olympus. Similarly to the Saint Seiya version of Hades, in the game Persephone seeks to eradicate the entire world due to her view that all humans are selfish and corrupted. She additionally sought to destroy gods (as Hades wants to destroy Athena) due to their "betrayal", and then inability to save her when Hades tricked her into marrying him. Another parallel is that both, in full armored form, resemble dark angels or angels of Death.
 * Hades' possession of the purest souls resembles his abduction of the pure maiden Persephone.