Hermos

Hermos was a legendary knight from the city of Atlantis, who aided Ironheart in the battle of Atlantis.

Background
Hermos, and the other two legendary knights, Critias and Timaeus mostly resided in the Duel Monsters World, until the city of Atlantis became corrupt by the Orichalcos. Ironheart had 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 three Legendary Dragons, had fought alongside rebels from the city of Atlantis and more Duel Spirits had fought 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.

Personality
His personality is similar to Joey's.

Appearance
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.

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 and 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 won the Duel.

However The Great Leviathan, was Summoned again. Hermos took part in the battle against it, this time his side emerged victorious. He along with Timaeus, Critias and Dark Magician Girl appeared on the beach to thank Yugi Muto, and Yami Yugi before returning to the spirit world.

Quotes

 * We will defeat you!!

Critias
He doesn't seem to have a rivalry with him.

Trivia

 * He doesn't appear in the Manga.

Voice Actors
all information on Hermos came from http://yugioh.wikia.com/wiki/Hermos
 * Japanese : Hiroki Takahashi
 * English : Wayne Grayson