Yugi and friends approach the Castle of Dark Illusions, but their progress is blocked by an army of monsters. They tear apart the flying machine and kill Adena's fairy companion, Earu, enraging Yugi so much that he lets Yami Yugi take over. While the heroes use Winged Dragon to carry themselves to safety, Mokuba is brought before the Witty Phantom. He has Kaiba's deck with him, though, and uses Swordstalker to free his brother. The Phantom turns and runs, but Seto's Blue-Eyes White Dragon wipes him out. Seto and Mokuba escape just as Yugi and his friends enter, and it seems the game is over...
But the Big Five have other plans. They override the game, and attack the heroes directly with the Mythic Dragon, negating the need for sacrifices. The Dragon has an astonishing 5000 Attack points, and to make matters worse, only Dragons can attack thanks to a Dragon Symbol on the floor. They target Mokuba first, since he has no monsters to defend himself, but Joey and Mai get in his way to protect him, digitizing and vanishing from the game. Yami tries to convince Kaiba that they must work together to succeed, but he won't have any of it—until Mokuba steps in the way of an attack aimed for Seto, and is killed.
This convinces Kaiba to cooperate, and he and Yami summon Dragon Master Knight to defeat the Mythic Dragon. They reappear at Adena's palace, and she honors their bravery by showing that she is in fact the Mystical Elf. With her magic, she brings back Earu, Joey, Mai, and Mokuba, and the heroes return to the real world safe and sound. Kaiba sincerely thanks Yugi for helping before they leave.
This episode contains examples of:
- Beam-O-War: When the dragons face off against each other.
- Dwindling Party: Yugi's friends are digitized one by one once the Mythic Dragon is unleashed until only Yugi and Kaiba are left.
- Hoist by His Own Petard: Mythic Dragon's presence and it having destroyed Red-Eyes Black Dragon and Harpie's Pet Dragon gives Master of Dragon Soldier enough Attack points to destroy Mythic Dragon.
- Just in Time: Yugi and the others step out of their in time as Kemo and the rest of the Big 5's thugs got through Tristan and Tea's barricade of the door.
- Mythology Gag: Yugi being driven to tears at Earu's death is similar to his reaction to his virtual pet dying in the manga.
- Oh, Crap!: Witty Phantom freaks out when Kaiba (just freed by Mokuba and Swordstalker) busts out the Blue-Eyes White Dragon and starts blasting everything in sight.
- Taught by Experience: When Armed Ninja show up to use the Dragon Capture Jar to steal another Blue Eyes White Dragon from Kaiba, this time he uses the Trap Master destroy the Dragon Capture Jar, allowing Kaiba to get his Blue Eyes White Dragon back.
- Teeth-Clenched Teamwork: Kaiba is forced to cooperate with Yugi's plan to defeat the Mythic Dragon.
- Wham Shot: Adena turning into the Mystical Elf.
