"Unleashing the Dragon, Part 1", known as "Threat of the Three Phantom Demons! Judai VS Martin" in the Japanese version, is the one hundred and twenty-ninth episode of the Yu-Gi-Oh! GX anime. It first aired in Japan on March 28, 2007 and in the US on November 23, 2007.
Bastion deduces that having "Rainbow Dragon" fight the Sacred Beasts should provide enough energy to unlock its full power and allow them to go back to Earth. Meanwhile, Jaden expresses concern that he may not win against Marcel. Hassleberry reminds him he's defeated the Sacred Beasts before. Jaden responds that he only won due to the card that Professor Banner had given him, and that card had faded away when the Duel was over, so he no longer has it.
Surrounded by Duel Ghouls once more, Jim, Alexis, Bastion and Hassleberry break through as Jesse and Axel separate from the main group to find the "Rainbow Dragon" card, with Jesse promising to get back to Jaden as soon as possible (In the Japanese version he wanted to stay and protect Jaden instead of leaving and was urged into it by Axel). With the way clear, the rest of the group heads towards Marcel. Jaden's friends provide distractions by occupying the Duel Ghouls once outside, while Jaden and Blair continue on.
Jaden reaches Marcel, and finally realizes that it's not really Marcel he's dealing with. He accuses him of manipulating Professor Viper, with Marcel responding that that's correct, it was all to revive the Devil Arm. Jaden realizes that whoever is possessing Marcel has known him all along. The demon responds that it will will make Jaden pay for abandoning it and wishes for revenge (in the Japanese version, it instead makes a proclamation of love to him).
Jesse and Axel are assaulted by monster spirits, with Axel firing multiple copies of "Volcanic Rat" out of his Duel Disk to defend Jesse, who eventually finds the card using "Crystal Beast Cobalt Eagle". The spirit of "Rainbow Dragon" then protects Jesse from "Sand Doodlebug" after Jesse dangerously leaps into a crater to stop the missile from sinking in sand. Jesse is delighted by the prospect of completing his deck, but Axel reminds him about how he promised Jaden to return as soon as possible. The Duel between Marcel and Jaden begins, and Marcel sends the Sacred Beasts to the Graveyard and begins Summoning monsters with 0 attack points. Perplexed, Jaden falls into his trap. Jesse arrives, and Marcel agrees to let Jesse join the Duel as Jaden's partner, with Marcel's Life Points doubling. When Jesse arrives, the demon comments to itself that Jaden's demeanor changed and becomes jealous of Jesse.
"Phantom of Chaos" then attacks and destroys "Sparkman". Due to the second effect of "Phantom of Chaos", Jaden takes no Battle Damage, but the effect that "Phantom of Chaos" got from "Hamon" then activates, inflicting 1000 damage to Jaden (Jaden 2000 → 1000). Marcel then Sets a card. On Marcel's End Phase, the effect of "Phantom of Chaos" expires ("Phantom of Chaos": 4000 → 0/4000 → 0). At this point, Jesse Anderson joins the Duel and goes to Jaden's side. They agree to grant Marcel 4000 extra Life Points due to Jesse entering the Duel with full Life Points (Marcel 4000 → 8000).