| Dokindam X |
The creature spirit has so far never been seen on its own, but it has possessed its owner Basara and acts through him. True to its appearance and nature, it was quite destructive, seeking to destroy anything who stands in its way.
It holds immerse power, even capable of manifesting its own powers and abilities outside of duels. When its powers manifest, it causes unimaginable destruction, causing massive damage and endangering both duelists and creature spirits alike.
Even Shobu Kirifuda, one of the legendary duelists with relations to the creature world and have some experience in Duel Masters related incidents know that its existence may endanger the world of Duel Masters, to the point of making him interfere even though he might endanger himself and his identity from others.
It later exchanged itself with a much more destructive Forbidden King, Dormageddon X, Forbidden Armageddon. This being is truly a mindless destructive entity as it manipulates its host's destructive urges into the point that he will be greatly mutated to the point that it is no longer human, and seeks nothing other than destruction of the planet. Even in the brink of its own destruction, Dormageddon X attempts to take the lives of other spirits along with it. This eventually affects the new future of dueling, as Dragons no longer exist in the new generation.
The card was used by Zakira to destroy duelists a long time ago during Shobu's time. However, its sealed form (Forbidden) was kept in the basement of Duel Masters Land which only Duemouse and Duema Land President knew its existence. One of its forms, Dokindam X, The Legendary Forbidden was kept in a dimensional space in the destroyed tower in Antarctica where Shobu defeated Adam 10 years (estimated time) before Duel Masters Land's opening.
As Katta and Shobu's ancestor Z Kirifuda and their grandfather Katsuzo Kirifuda have some prior knowledge of Dokindam X before its release, this means that the dark creature spirit have existed way before Shobu's time. The Kirifuda Family played a role in sealing Dokindam X to its Forbidden state to prevent its true form Dormageddon X, Forbidden Armageddon from approaching both the human and creature world. However, due to it likely being forgotten generations later, Forbidden was obtained through unknown means by Zakira.
Duel Masters Versus Revolution
In desire for revenge against Lucifer, Basara entered the basement with Duemouse and the card's spirit communicated with Basara for its desire to be free, destroying the seal of the card under its orders. Then Basara went to Antartica under the guidance of the card and entered the destroyed tower, where he was challenged by Zakira which was actually frozen, and became active after the dimensional field was activated. While Zakira put the duel in a stalemate by All Delete, he still let Basara have the true form of the card, Dokindam X, The Legendary Forbidden and Basara escaped.
After obtaining the card, the spirit quickly took over Basara and replaced his personality with its own, which had him hungering the destruction of all duelists just like Zakira. Basara then quickly defeated Lucifer and Katta, but Katta had a rematch with Basara and when Katta was about to win him with the two Dogiragons, the worse effects of the spirit appears and took over his right hand, which caused the President to stop the duel by destroying the duel table and taking the card and Redzone, Roaring Invasion.
The card was later re-obtained when Basara, Hakase and Rambo stormed the Duel Masters Land Fortress with Hakase and Rambo distracting Zon-san so Basara can get the card. When Basara enters the top floor he regained the card and defeated the president.
After re-obtaining the card, the possession by the creature spirit has become even more serious that Basara's right hand was replaced with a claw and both his hands had an x on them. Forbidden characters also appear on his right arm and bandages were placed around it to constrain the spirit's power.
Duel Masters Versus Revolution Final
Later on, Basara and his friend Number 2 and a few other heretic duelists formed an organization named Rare Killers who stole rare cards. After sending a few members who got thwarted by Katta and co., Kojiro gave Basara a copy of Digurupion, Earth Snake and it was fed to the card's spirit and the card became blank, and it was known that the organization's objective was to feed the creature spirit with rare cards, with each one making the spirit more powerful. The card also changed appearance as it absorbed numerous rare cards. After then, Basara challenged Katta in the place where they last fought and when he was drawing a D2 Field, his pupils had gained into an X symbol, his right arm became black, and the spirit also caused his dueling tactics to be more brazen.
In a gag episode, a Dokindam X who dressed as a stereotypical mother appeared as a joke character called "Miss Dokindam Mother".
After absorbing some creature spirits, the dark creature demands for more, resulting in Basara gaining a hunger in obtaining more rare cards. The gang assaulted the school Katta was in in order to get the creature spirits. In the duel, Dokindam X used and attempts to direct attack Lucifer, but was stopped by a Revolution 0 Trigger. It was struck down by Miradante Twelve, Time Pope but later on releases its true potential upon Basara's call. However, this results "Victory Mode" activating and induces great pain to Katta. Katta then sees a vision of Dokindam X's possibility to reveal the True Forbidden once it was released from its shell in a form of FORBIDDEN ~Star of Forbidden~, which later appeared with the transformed Basara and an unconscious Number 2.
Due to its power growing through Basara's darkest desires, it transformed into Dormageddon X, Forbidden Armageddon. This has reached to the point that the Revolutionary creature spirits sense its ominous presence, even Dragon Ryu as some witnessed the scarlet moon.
Dormageddon X (Basara) then dueled Kojiro and when it manifests, Kojiro was never seen again, and when it (Basara) dueled Katta its real effects were revealed and after escaping an Oriotis Judge, it destroyed Katta and in there it was revealed that the duelists destroyed by Dormageddon X were sent to a subspace as Kojiro was seen there. However Ryusei the Earth enters the subspace and saves Katta. The spirit then manages to take over Basara fully for a while trying to kill Katta physically before it was suppressed by Number 2 and he and Basara left via bike.
Basara eventually mutates even more due to mostly relying on its power, to the point that its final form, Dormageddon X descent from earth was visible among the space cameras and some data, even in the real world in which Basara lost his entire humanity and shot out in space for it for his nihilistic goals. Even though Dormageddon X's sealing ability seems to be unbreakable, it was proven to have a flaw as Team Hamukatsu's Explosion Go! was capable of sending the card used as a seal to the mana zone instead of the graveyard. Katta uses the Team Spell to his advantage to release Hamukatsu as Hamukatsuman Ace, Brave 1 from the seal by sending the card used into the mana zone.
Final Dogiragolden then uses its Final Final Revolution to lockdown Dormageddon X and secondary ability reduces the Armageddon creature to its central core. However, Dormageddon X was powered by Dordrain, Final Forbidden Beta, rendering Dogiragolden's lockdown ability useless. Dormageddon X was finally struck down by Final Dogiragolden, powered by Hamukatsu as Curry Bread of the Universe. However, it still retain its will to destroy, even self destructing and taking Dogiragolden with it. Ironically, it was destroyed by a descendant of the family who sealed its Forbidden state in the first place.
While the being is permanently destroyed, its destruction resulted in the destruction of all Dragons in the creature world in Joe Kirifuda's saga, causing Deckie to be unable to create Dragon-like creatures.
- It was the fourth creature spirit to be a major antagonist in the anime, preceded by Diabolos Zeta, Temporal Ruler in Cross Shock, the Aliens that make up Gallows Hellish Dragon, Brink of Despair in Victory and the Oracles in Victory V3.
- Dormageddon X was one of the few creature spirits who made an on-screen kill to a duelist since the previous generation.
- However, in reality the duelists were just hidden from the real world.