Doma is the name of an ancient secret society which tried to take over the world using the Orichalcos. It is also called the "Doma Organization".
It has been lead by Dartz, who also controls the company Paradius, which aids Doma. Since Doma is unnamed in the English anime, it is a common misinterpretation that Doma is simply the Japanese version name for Paradius.
In the present day, Dartz hired Raphael, Alister and Valon as his "swordsmen" and used them to trap people's souls using the "Seal of Orichalcos". This was to awake the god of Orichalcos called the Great Leviathan. The members eventually realized that Dartz had actually caused all the incidents to encourage members to join.
This group was no more after all its members' souls were forfeited upon loss in duels and the Paradius conglomerate became disbanded before the final battle between Yami Yugi and Dartz.
- Dartz - Creator of the Doma Organization, loses his soul in the duel against both Yami Yugi and Seto Kaiba. Called Master Dartz by his followers. In his 2-on-1 duels with Seto Kaiba and Yami Yugi, he defeats Kaiba (claiming his Soul) but loses to Yugi. Took Raphael's soul during his duel with Yugi and Kaiba in response for his rage at him when he reveals that he is responsible for his life falling apart.
- Alister - Joined the organization after his brother was killed (kidnapped in the English Version); plays a Gorlag/Machine deck, duels Seto Kaiba twice, lost his soul in the second duel against Seto Kaiba.
Ties against Seto Kaiba in his first duel with him. Loses the duel and his soul in his second duel with him.
- Valon - Joined the organization after being held captive in a detention center; plays a brutally rough Armor deck, duels Duke Devlin and Rebecca Hawkins in a 2-on-1 duel, then dueled Joey Wheeler; lost his soul in the duel against Joey Wheeler. Defeats Rebecca & Duke Devlin (but does not claim their souls as he does not use the Seal).
Lost his duel and soul in his duel with Joey Wheeler.
- Rafael - Joined the organization after losing his family in a shipwreck; plays a Guardian deck, duels Yami Yugi twice (winning and losing) and dueled Mai once; lost his soul when enraged against Dartz. Defeats Yami in his second duel (he forces him to play the Seal of Orichalcos); though only Yugi's soul is claimed, Yami's is left behind. Defeats Mai Valentine after she betrayed Dartz and took her soul. Loses to Yami; due to how his heart's darkness was erased, he never lost his soul.
- Mai Valentine - Joined the organization to get rid of Joey Wheeler and to become stronger.
Duels, beats, and steals the soul of Pegasus. Duels Joey Wheeler; the duel is interrupted by Valon. Duels Joey Wheeler following his defeat on Valon; due to exhaustion, Joey surrenders, releasing Mai from the Orichalcos' influence. Duels Rafael after betraying Paradius; loses her soul.
- Gurimo - Joined the organization for unknown reason(s); appears in the 1st two episodes of the season.
Duels, beats, and steals the soul's of Weevil and Rex. Duels Yami Yugi, loses the duel and his soul.
- Rex Raptor - Joined the organization in thirst for power after witnessing Rafael beat Yami. Duels Gurimo with Weevil and loses is soul but is released by Rafael. Duels Joey Wheeler; loses the duel and his soul.
- Weevil Underwood - Joined the organization for the same reasons as Rex Raptor. Duels Gurimo with Rex and loses his soul but is released by Rafael
Duels Yami Yugi; loses the duel and his soul. Orichalcos Soldiers are creations of The Great Leviathan. They served Dartz and aided in his conquest of Atlantis.
- Orichalcos - The supernatural sorcery that is the source of the Orichalcos God's power. It serves as the core of Dartz's ideology as well as the driving force behind the machinations of both the corporation Paradius and the cult-like group Doma.
- Orichalcos God (also known as the Great Leviathan) - The monstrous Orichalcos deity featured as the main antagonist in the "Waking the Dragons" story arc.
- Orichalcos Stone - The crystal that powers the magical "Seal of Orichalcos" in the Waking the Dragons arc. There are many fragments of the original and once completed Orichalcos Stone that fellvand arrived upon the lost city of Atlantis during a meteor shower centuries ago, and they are currently in the possession of Dartz and his followers.