Alone (Arōn) is a young painter and also Hades' previous incarnation. He is an Italian orphan raised alongside Sasha and Tenma, who later become arch-enemies. He is the purest soul on earth and believes that everybody has a good side and disapproves the use of violence, which is why Hades chose to reincarnate in his body. At first he rejects his fate as the God of the Underworld, but is convinced later 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 makes a drastic change after seeing 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 reaches of anyone from his childhood life.