Astral ist verschwunden – und das bereitet Yuma enormen Kummer, der bald gewaltiger Wut weicht. Er gibt den Karten die Schuld an der Misere, und selbst seine Freunde Tori, Bronk, Flip, Cathy und Caswell können Yuma nicht aufheitern. Währenddessen plant Don Tausend, Unruhe und Leid über die Menschen-Welt zu bringen.
As Yuma remains reclused following Astral's disappearance, Don Thousand gives Vector the remnants of Number 96's power, who is revealed to be a shard of Don Thousand's malice that was trapped inside of Astral, during Astral's ancient battle with Don Thousand. Number 96 is also revealed to be a "Forbidden Number." Then, Don Thousand reveals his plan to use his new powers from Number 96 to make multiple Dimension Fusing Devices, to merge the Human World with Barian World, once the level of evil in the Human World reaches that of Barian World. This would increase Don Thousand's power by a thousandfold, giving him enough power to destroy Astral World. In order to create more Dimension Fusing Devices, Don Thousand emerges from Vector's body in a black energy form resembling his true likeness, and fuses Vector to his throne, in order to concentrate their energy on making more Dimension-Fusing Devices. Then, using his newly enhanced powers, Vector returns Mr. Heartland to his human form, grants him four Fake Number cards, and gives him a group of 3 Barian servants, who, along with Mr. Heartland, make up the Fearsome Four of the Dark Dueling World. Mr. Heartland distributes 3 of the Number cards among the other members of the Fearsome Four, while he keeps Number 1. Soon afterwards, a servant named Semimaru begins attacking duelists and stealing their memories. When Tori and the others try looking into the incident to cheer Yuma up, they are caught by Semimaru, who steals their memories and uses them as bait to lure Yuma into a duel. Heartland attempts to coerce Yuma into giving up his Numbers to save his friends, but he remains determined to cling onto the Numbers that Astral had left him. He is soon joined by Trey, who offers to support Yuma in a 2-on-1 duel against Semimaru. However, Mr. Heartland uses Don Thousand's power (which manifests in a crest-like form of Don Thousand's Barian Emblem) to activate a field effect, which puts Yuma and Trey at a distinct disadvantage
