Dartz narrates the history of Atlantis: it was a peaceful city in which harvests were copious, there was no greed or vanity. People lived in harmony with the Land and the Spirits (the Duel Monsters). Dartz became hereditary King after his father, Ironheart, resigned due to age. He had a wife, Iona, daughter, Chris, and their pet Skye.
However, one day, a volcano erupted and a 'gigantic black dragon' swallowed the Sun and stones rained down on the city: the Orichalcos was born. Dartz explains that it was a treasure granted to them by Earth itself: anyone would've thought so. Why? Because it can become energy, medications and industrial products among other uses: they labelled it a miraculous material. Atlantis' civilization evolved in very quick manner, becoming even more advanced than modern civilizations.
However, they didn't notice something: the people's hearts were slowly beginning to become corrupt due to desire appearing and making people become the gathering ground for the Dark.
He then compares the 21st century's society to that of his age: a world full of useful material has caused the people to forget to be thankful to the Land and the Spirits. People live in an imagination-less reality and have lost most of their emotions. There are no crueler living beings than humans.
The inhabitants started to become "Monsters" and chaos ensued: Dartz was forced to slay his wife once she become an ugly beast. Blood was shed in Atlantis: the fountains began to be stained.
Confused, Dartz sensed a powerful energy coming from an Orichalcos fragment: it turned his left eye into its current turquoise color and shown a vision of a gigantic serpent-like creature pulsating inside of the Earth iself. He claims that he then understood everything: the Orichalcos wasn't a miraculous material. It was a test issued to them from the Earth itself, and they failed it. It was meant to amplify the 'Dark' inside of humans. He claims that the humans would end up destroying themselves, and that he was tasked with reviving the Great Leviathan and purging the Earth of humanity to restore "Paradise".
When Ironheart tried to convince him to abadon Orichalcos, Dartz politely replied that even if they did so, the inhabitants wouldn't return to normal. He then went on saying that Earth itself had granted him a command: to allow for the Orichalcos God to descend in order to destroy the corrupt humans and create a new world of perfect humans. They were supposed to protect the planet, but they had failed.
Dartz is granted command over the Orichalcos Soldiers, so Ironheart, Chris, and Sunny run off, knowing that Dartz has gone mad. Dartz ignores them and announces that a new God shall descend upon the world.
However, Ironheat and Chris escaped Atlantis and requested help from the world of Duel Monsters: these events led to the Battle of the Stone Wasteland. It ended in a stalemate, with Ironheart's side destroying the Orichalcos God.
Dartz goes on saying that, before his death, Ironheart "sealed" the "door" of the Duel Monsters world, leaving some of their relics scattered around the world: the Pyramids, the Aztec pyramids, the mastabas, the Greek temples...
He's waited 10,000 years, but the result is the same: humans keep on being corrupt and he must purge this world of them.
When Kaiba claims that they've already defeated him, Dartz laughs and tells them to closely survey his powers.
The 2nd "Seal of Orichalcos" and the "Mirror Knights"
The three of them return to the 'real world' and both Kaiba & Yugi gasp upon seeing that Dartz still has 3500 LP and that their Attack did nothing: that was the Special Ability of "Orichalcos Kyutora".
He then goes with the strategy of resurrecting "Orichalcos Gigas" and making him become a wall to keep "Kyutora" safe. Along the way, he plays "Orichalcos Deuteros", the 2nd "Seal of Orichalcos". It allows him to gain 500 Life Points per every Monster on his side of the Field.
Meanwhile, Rafael has disembarked on the island and is heading towads the top of it.
These "Mirror Knights" also possess the Special Ability of copying an enemy Monster's ATK and easily Destroy them. Even though Monsters with the same ATK Destroy each other, the "Mirror Knight Tokens" have their "Mirror Shield" which can be sacrificed to avoid their Destruction, and "Mirror Knight Calling" has another Special Effect: it can regenerate the shields.
Thus, both Duelists are pushed into a tight corner. Kaiba uses "Kaiser Glider" to make sure Dartz can't pull the "Mirror Knight Tokens" Special Effect on him, making Dartz look amused.
However, the helmets of the "Mirror Knight Tokens" shatter and fall into the ground: they are in truth the souls of Yugi, Mai, Joey, and Pegasus, who have been turned into these forms. Yami Yugi gasps upon remembering how he was planning on using "Mirror Force" on them and wonders if he'd killed them then.
How will Kaiba and Yami Yugi get out of this situation?
Turn 6: Dartz
Due to the effect of "Orichalcos Gigas", Dartz must skip his next Draw Phase. Dartz then activates "Orichalcos Deuteros". This card gains all the effects of "The Seal of Orichalcos", plus a few effects of its own. Dartz then activates the first effect of "Orichalcos Deuteros" to gain 500 Life Points for each monster he controls. He currently has two (Dartz 3500 → 4500).
"Orichalcos Gigas" attacks "Master of Dragon Soldier". "Master of Dragon Soldier" destroys "Orichalcos Gigas", but the effect of "Orichalcos Kyutora" nullifies the damage. Dartz then activates the effect of "Orichalcos Gigas" to Special Summon the latter monster from his Graveyard in Attack Position with 500 more ATK than previously ("Orichalcos Gigas": 1400 → 1900/1500) by skipping his next Draw Phase.
Turn 7: Kaiba
Kaiba draws. He then Sets a Card and Normal Summons "Blade Knight" (1600/1000) in Attack Position. Since Seto has at most one Card in his Hand, the effect of "Blade Knight" increases its ATK by 400 ("Blade Knight": 1600 → 2000/1000).
Turn 8: Yami Yugi
Yami Yugi draws. Seto then activates his face-down "Reflect Energy" to Tribute "Blade Knight" and allow Yami Yugi's Monsters to attack directly this turn. "Master of Dragon Soldier" attacks directly, but Dartz activates the second effect of "Orichalcos Deuteros" to Tribute "Orichalcos Gigas" and destroy "Master of Dragon Soldier". Yami Yugi then activates "De-Fusion" to return "Master of Dragon Soldier" to the Fusion Deck and Special Summon "Black Luster Soldier" (3000/2500) and "Blue-Eyes Ultimate Dragon" (4500/3800) from the Graveyard in Attack Position with "Black Luster Soldier" on Yami Yugi's side of the field and "Blue-Eyes Ultimate Dragon" on Kaiba's side of the field. Since "Master of Dragon Soldier" left the field, its attack is negated.
Turn 10: Kaiba
Kaiba draws "Card of Demise" and subsequently activates it to draw until he has five Cards in his Hand (his Hand is empty so he draws five cards). Five Turns after the activation of "Card of Demise", Seto must Discard his entire Hand during his Standby Phase. Kaiba's hand is shown to contain "Silent Doom", "Kaiser Glider", "Cost Down", "Ring of Destruction", and "Attack Guidance Barrier".
Kaiba then activates "Silent Doom" to Special Summon "Blade Knight" (1600/1000) from his Graveyard in Defense Position. He then Tributes "Blade Knight" in order to Tribute Summon "Kaiser Glider" (2400/2200) in Attack Position. Due to this card's effect, it can't be destroyed in battle by a monster with the same ATK as it. Kaiba then Sets a Card.
Turn 12: Dartz
Dartz draws. He then activates the first effect of "Orichalcos Deuteros" (Dartz 7500 → 10500). Seto then activates his face-down "Ring of Destruction" to destroy Dartz's "Mirror Knight Calling" and inflict damage to Seto and Dartz equal to the ATK of "Mirror Knight Calling" (Dartz 10500 → 10000; Seto 3500 → 3000). At this point, it is revealed that the Mirror Knight Tokens have the souls of Yugi, Joey, Mai, and Pegasus.
In the original, when Dartz finds the beast, the beast drops the queen's body. The queen's body is removed from the dub.
Cut from the US version are shots of the beast attacking Dartz, who draws his sword and kills it. Then the fountains' waters turn the color of blood.
When Kaiba summons "Blade Knight", he says that its effect gives it 400 extra ATK points because he has 1 card left in his hand when he actually had none. This is probably due to "Blade Knight"'s effect working when the owner's hand is 1 or less.