Duel Dragon

"Duel Dragon" (, Dyueru Doragon) is a series of dragonic monsters used by several key characters in the Yu-Gi-Oh! 5D's Manga. They are said to be cards specifically designed for Turbo Duel rituals in ancient times. Six of the "Duel Dragons" shown are counterparts of the "Signer Dragons" from the anime, and play a similar role in the manga.

The "Duel Dragon" cards are ancient cards, who are held by the Skeleton Knight and Rex Goodwin in the present. They possess a massive dark power, enough to control their own holders if they are unable to tame them. A man who holds a "Duel Dragon" becomes a Duel Priest, while a woman becomes a Duel Priestess.

Etymology
In the Japanese version, the names of all "Duel Dragons" have the following composition: "(Adjective 1) (Adjective 2) Dragon - (Name)" with the adjectives and "Dragon" written in Kanji and the name in Katakana. Some have two adjectives, while some have only one, still, all Level 8 "Duel Dragons" have two Kanji characters for the adjective(s), and all Level 10 "Duel Dragons" have three. The kanji of each dragon that is based on a Signer Dragon from the anime ends in "竜", while the ones original to the manga end with "龍".

In English, the names of the "Duel Dragons" gain the composition "(Name) (Adjective) (Dragon)". Most of the Dragons which have anime counterparts keep the name of their anime counterparts with the addition of an adjective, such as "Stardust Spark Dragon", who is a counterpart of "Stardust Dragon".

Appearance
The majority of the series are Dragon-Type Synchro Monsters (the exceptions are "Power Tool Mecha Dragon", which is a Machine-Type and "Dragonecro Nethersoul Dragon", which is a Fusion Monster). Some of the "Duel Dragons" have marks that resemble the Mark of the Dragon somewhere on their bodies. Both "Power Tool Mecha Dragon" and "Ancient Pixie Dragon" that resemble their anime counterparts can be considered dark counterparts via their Dark Attributes and alternate effects.

The "Duel Dragons" which are "Signer Dragon" counterparts often have a darker colour scheme than the original, though "Stardust Spark Dragon" and "Blackfeather Darkrage Dragon" only demonstrated this when being used by the Priest of Light and Dark Crow respectively. Jack's "Hot Red Dragon Archfiend" does not appear to exhibit a darker colour scheme, but this is difficult to discern to to the natural colour of the "Duel Dragon". "Power Tool Mecha Dragon" also exhibited a lighter colour scheme after being purified by "Stardust Spark Dragon", though this may have been a product of the severe damage it had suffered after being destroyed and then revived.

Abilities
"Duel Dragons" possess a strong miasma which causes their owners' personalities to become darker, or even takes over them. When this happened to Kalin, Jack angrily asked if his "Duel Dragon" had eaten his soul, suggesting that Kalin had failed to control the dragon and was instead being controlled. The signs of the strength of the bond with a "Duel Dragon" have many stages; those who have not gained dominion over the dragon properly often have blank eyes and a progressively darker personality, often emitting Shadow Miasma. Further succumbing to the "Duel Dragon" can lead to the skin of the face cracking and/or the whites of the eyes turning black, though all of these symptoms can be removed when purified.

They also appear to have more occult powers; When attacking Yusei, Leo's dragon showed him memories from Leo himself, while when Sect got mad at the Skull Flames, his "Duel Dragon" card's miasma instantly caused them to fall on the ground unconscious. Furthermore, Rex Goodwin was able to pass memories of Akiza's past life directly to her mind by just making her have contact with a "Duel Dragon" card. "Stardust Spark Dragon" was able to show Yusei Fudo its own memories when he engaged in a One-Shot Run against it.

However, the negative influences can be removed when a "Duel Dragon" is purified by another dragon. The only way to sever the link between a "Duel Dragon" and its holder is in a Duel. It usually happens when another "Duel Dragon" destroys the corrupted dragon, which is first demonstrated when Jack's "Hot Red Dragon Archfiend" clashed with Kalin's "Void Ogre Dragon". Kalin's Shadow Miasma was removed, and he returned to his original personality. Yusei Fudo's "Stardust Spark Dragon" later destroyed both "Power Tool Mecha Dragon" and "Ancient Pixie Dragon", freeing first Leo, and then Luna. Yusei would theorize that destroying "Beelze of the Diabolic Dragons" with "Stardust" would free Sect Injuin" from the "Duel Dragon", which was later proven to be true.

History
According to Rex Goodwin, since ancient times, Turbo Dueling has been a ritual designed to fight and seal the darkness, and that the "Duel Dragons" were specifically designed for such rituals. In the past, they were fought on horseback. He says they are cards which sealed the dragonic power of the priests who controlled them, and adds that controlling or being controlled by that power depends on the strength of the Duelist's mentality. Because of that, he organized the D1GP in order to gather Duelists with strong mentality in order to control the "Duel Dragons", and according to him, save the world from Skeleton Knight. However, his true intentions were later revealed to be reviving and controlling the Ultimate God through the Ritual, to which he needed strong Duel Priests and Priestesses. Five dragons ("Stardust Spark Dragon", "Hot Red Dragon Archfiend", "Blackfeather Darkrage Dragon", "Ancient Pixie Dragon" and "Power Tool Mecha Dragon") belonged to Priests of Light in the past, plus "Black Rose Moonlight Dragon", who belonged to a Duel Priestess. They were passed to new Priests and Priestess in the present by Rex and the Skeleton Knight, reviving the ancient ritual.

Usually, the "Duel Dragons" cards are blank, and only take form after obtaining a holder. Rex Goodwin and the Skeleton Knight seem to possess all of the "Duel Dragon" cards in the present, and distribute them to powerful Duelists, which they choose through several methods. Some include:
 * Sect Ijuin obtained his "Beelze of the Diabolic Dragons" personally from the Skeleton Knight via an oath, in exchange of his services.
 * Yusei Fudo had to undergo a ritual involving the Dragon's original owner in order to obtain it. It was placed by Rex in a Duel Zodiac.
 * Jack Atlas obtained a blank "Duel Dragon" personally from Rex, which took form right after being held by him, after defeating Kalin Kessler and being recognized as the V.S.S.L.'s strongest Duelist.
 * When Crow Hogan passed by a blank "Duel Dragon" card, the card's black aura took form of a dark version of himself, and if Crow defeated it, he'd obtain the Dragon, which he was able to accomplish. It was placed by Rex in a Duel Zodiac.
 * Akiza Izinski received a blank "Duel Dragon" personally from Rex so that she could become the Duel Priestess and participate in the ritual to revive the Ultimate God.
 * Leo got his "Duel Dragon" from Lazar, under Rex's orders, after he got beaten up by people for losing Duels and making them lose money when they had placed their bets on him.
 * Kalin performed an oath and received his "Duel Dragon" from the Skeleton Knight.

Although how she obtained her "Duel Dragon" has not been specified, Luna most likely obtained hers from Rex.

After Rex obtains the Ultimate God's power, he reveals that all cards, including the "Duel Dragon" cards, were born from the Ultimate God, who is their master. With the Ultimate God's power, Rex gains control of the "Duel Dragons" of all Duel Priests and Priestesses, making their cards turn blank. However, their prayers ultimately awakens the dragons' souls and release them from the Ultimate God's control, allowing Yusei to use them for their real purpose: to seal the Ultimate God and save the world from its darkness.