With the five dragons merged into one being, the Five-Headed Dragon, things don't look good for Yugi and friends. As the dragon can only be defeated by creatures of light, Tea and Tristan attack it with their monsters, but Seiyaryu, Dark Witch and Thunder Dragon aren't strong enough. Yami Yugi fights valiantly, but the dragon strikes him down, and Yugi's friends are busy protecting the villagers. The maiden chosen for the sacrifice prays for the Blue-Eyes to aid Yugi, and, joined, by the prayers of the other villagers, it awakens. Yami merges with the Blue-Eyes and suplexes the Five-Headed Dragon before finishing it off with a White Lightning attack. All that's left of the dragon is a simmering crater. With that, the fifth and final trial is complete, and the group is able to return home.
Before they go, though, Alexander further reveals that the Millennium Ring split his soul in two—the side they've met is peaceful and kindhearted, while the other is his ruthless, war-mongering side. While Alexander's good half was trapped in the Capsule Monsters world, his dark half was locked in the pyramid and now possesses Alex Brisbane, who happens to be a direct descendant of his. Once Yugi and his friends return to their world, they must use Tea's pendant to open a doorway at the top of the pyramid, where Yugi will be granted ultimate power—it's imperative that he claim it before Alex does.
Yugi and his friends concentrate and are able to return home, while Alexander hitches a ride with Solomon Muto in the hopes of overpowering his dark half and freeing Alex. Brisbane asks if they found anything interesting while they were there, and as Solomon holds out the pendant to distract him, the two Alexanders merge. Brisbane claims to be feeling better, and everyone is happy that the plan worked... Until he snatches the pendant away.
Alexander's evil half won out, and he easily suppresses his good half and runs for the door. Yugi and his friends give chase, but Brisbane has opened the door to ultimate power, and when Yugi and Tristan attack him physically, he backs them all into the open doorway. Everyone falls into a new dimension that resembles outer space, and Shadi suddenly appears before them...
This episode contains examples of:
- Cue the Sun: The sun rises after Yami slays the Five-Headed Dragon.
- Deus ex Machina: Literally. When Yami is injured in the fight against the Five-Headed Dragon, the girl chosen as a sacrifice prays for the Blue-Eyes to aid him, joined by the other villagers. It awakens and aids Yugi.
- Final Boss, New Dimension: After Alexander opens the final door, everyone finds themselves in a new dimension where they must battle him for the fate of the world.
- Helpless Good Side: While Alexander's good half is able to assist Yugi and his friends, when he merges with his evil half the evil side wins out, suppressing him completely until he's destroyed.
- Hyde Plays Jekyll: Alexander poses as Alex Brisbane when the group meets him, and when the good Alexander attempts to reunite with and overpower his other half, he pretends to have been freed to trick Yugi's grandpa.
- Jekyll & Hyde: The Millennium Ring split Alexander's soul into two halves, one his peaceful side and the other his war-mongering side. The evil side notes that without him Alexander could never have conquered half the globe.
- Sharing a Body: Alexander merges with Solomon Muto to get back to the real world.
- Split-Personality Merge: Alexander tries to do this to overpower his dark half, but the evil side wins out and suppresses him.
