Hypnos, although allied with Hades, is a good bad guy; he want the victory of Hades and destroy the world, but with less empathy to his enemies, and don'twish to kill them; according him, the sleep is a non-deadly death, and uses schemes to don't kill the enemy, so, he don't attack his enemies impulsively in front, because he wants not kill them; he is astrategist guy too. But in Lost Canvas, he don't haveempathy, and only was a strategist.
With priest clothes, Hypnos guides Alone to place where he is possessed by Hades.
According Lost Canvas, Thanatos with Hypnos in the Holy War of XVI Century, did Athena die after Hades defeat. So, Sage and Hakurei gets worried by them menace.
In the Century XVIII holy war, because of his genius, Hypnos was most hardly defeated in this ark, and Hakurei tries arrest Hypnos in a box (where Thanatos was imprisoned), but die in the process.
In Lost Canvas, he was a great friend of Pandora.
In the Saint Seiya classic series, Thanatos and Hypnos were freed by Pandora and he and Hypnos promises to Pandora, eternal life if she cares aboutthe Hades soul and Hades host, being his elder sister. Pandora was brainwashed and only saw the worldaround she in gray and black colors, thought Hades will purify this world
But, when Pandora betrays Hades, Thanatos, with his wickedness, kills Pandora, disregarding all what she did to Hades. Hypnos rebukes his brothers, and tell to Thanatos that he kidnaped Athena, but didn't kill her, arresting her in a vase; he wants not shed blood in the Elysium
Seiya arrives in the Elysium, and meet Thanatos, that tries to kill Seiya, and Hypnos leaves Thanatos fighting with him, and wait in his temple; but, when remembered of the divine clothes and their menace, he goes notices it to Thanatos, but Seiya gets thedivine cloth and kill Thanatos. Seiya passes throughHypnos and he wants notices to Seiya, don't awake Hades body, but Ikki stops him. Shun gets the divinecloth and Ikki goes to help Seiya, but Hypnos does Shun sleep for eternity (his divine cloth saves him after), and Shiryu and Hyoga, with their own divinecloths, defeat Hypnos, worried with Hades body.