Devon Knox, ein wahrer Duellprofi, kommt in die Schule, um dort Duell-Spezialkurse anzubieten. Er wird jedoch von der Macht der Barian-Welt eingenommen und fordert Yuma zum Duell. Yuma kann sich durchsetzen, wenn auch nur knapp. Noch wichtiger als der Sieg ist allerdings, dass er auch einen neuen Freund gewinnt...
On his way to school, Yuma encounters an overly-positive, well-meaning transfer student named Ray Shadows and ends up getting dragged around by him. Meanwhile, a pro duelist named Devon Knox visits the school to have duels with the students. When Yuma expresses his interest in dueling him, Ray takes it upon himself to try and find Devon and convince him to duel. However, Devon is possessed by Girag and violenty duels against Ray to get Yuma's attention. Yuma begins a duel with him and summons out Number 34: Terror-Byte whilst Devon summons out his ace monster, Giantrainer. After using its effect damaging abilities, one of which backfires against him, Devon uses Rank-Up-Magic Barian's Force on Giantrainer to upgrade it into the Chaos Xyz monster Ultimatrainer, using its ability to test Yuma's drawing luck. Yuma manages to survive the effect and use the monster cards he was forced to discard against Devon before bringing out Utopia Ray and winning the duel, freeing Devon from the Barians' control.
