Hermos and the other legendary knights resided in the Spirit's World, until Atlantis became corrupt by the Orichalcos. Ironheart Summoned them to the human world, to help him defeat Dartz, who was trying to wipe out the population of Atlantis and start fresh. However Dartz weakened the knights by turning them into dragons.
The Legendary Dragons, fought alongside rebels from Atlantis and more Duel Spirits against Dartz, Orichalcos Soldiers and The Great Leviathan.
The battle ended with neither side victorious and Atlantis sunk to the bottom of the sea. The Dragons were sealed in crystal prisons, until they would be needed again.
Hermos, like other legendary knights, is named after Plato's work. Hermos is named after Hermocrates from Plato's dialogues Timaeus and Critias.
In his human form, Hermos wears red armor. Like the other knights he bears a similar facial expression to his chosen duelist, Joey Wheeler.
His red color scheme follows him into his dragon form.
Yu-Gi-Oh! Duel Monsters (Anime)
Waking the Dragons arc
Joey Wheeler was chosen as a Legendary Duelist to wield Hermos. During a Duel with Mai Valentine, he and Yugi were subconsciously taken to the Duel Monsters Spirit World, where they saw Hermos trapped in his prison. By removing a sword Joey set Hermos free and got the card "The Claw of Hermos", so that he may Summon "Hermos" while playing Duel Monsters.
As a card, Hermos had the ability to combine itself with monster to create Equip Spell Cards. Joey used it to form "Time Magic Hammer" in his Duel against Mai. He also used it against Rex to create "Red Eyes Black Dragon Sword", against Valon to create "Rocket Hermos Cannon" and "Big Bang Dragon Blow" and in his second Duel against Mai to create "Red-Eyes Black Dragon Sword" again.
After Joey lost to Mai, Mai had a change of heart stormed off to face Dartz taking the "Hermos" card with her. However she was confronted by Rafael, who defeated her and took the card. When Yami Yugi arrived, Rafael gave him the card, before they dueled. Yami Yugi used it in the Duel to create "Golden Bow".
When Yami Yugi and Kaiba faces Dartz, Yami Yugi used 'Legend of Hear" to change the dragons back to their true forms. Together with Timaeus and Critias, Yami Yugi was able to defeat Dartz's "Divine Serpent" and win the Duel.
However The Great Leviathan, was Summoned again. Hermos took part in the battle against it, this time his side emerged victorious. He, Timaeus, Critias and Dark Magician Girl appeared on the beach to thank Yugi Muto and Yami Yugi before returning to the spirit world.
Dark Magicain Girl
- He doesn't appear in the Manga.
- Japanese : Hiroki Takahashi
- English : Wayne Grayson
all information on Hermos came from http://yugioh.wikia.com/wiki/Hermos