Japanese Title: Showdown! Dark Knightmon VS Xros Heart!
DarkKnightmon's undead Digimon attack Xros Heart, who flee alongside Pinocchimon. Pinnochimon leads them to an abandoned factory. DarkKnightmon levels the factory as they escape through a garbage chute and land in another junkyard. Kiriha figures out that Xros Heart have escape through the garbage chute and DarkKnightmon reasons that they have to have allied with local Digimon to know that it was there. That night, Akari and Zenjirou speculate on how Kiriha came to work for DarkKnightmon, but are interrupted by Sparrowmon who tells Taiki that DarkKnightmon imprisoned Nene in the tower that he initially brought Taiki to. Sparrowmon also confirms that DarkKnightmon is forcing Nene to collect various forms of dark power for him by threatening her brother with the intention of creating a Darkness Loader. Starmon asks what they can do to help Nene's brother, but Taiki and Zenjirou agree that they need to help Nene first. Pinocchimon and his crew agree to help. Meanwhile, Lilithmon arrives in the Dust Zone with the small metallic Digimon. DarkKnightmon shows up to introduce himself to her and brags that he has power on par with the Bagra Army. DarkKnightmon further tells Lilithmon that as Kiriha works for him now, Kiriha's Code Crowns also effectively belong to him and then proposes an alliance between himself and Lilithmon to fight Taiki. Lilithmon agrees and DarkKnightmon explains that he plans to lure Taiki in with Nene as the bait. He also states that Lilithmon can take Taiki's Code Crowns when the battle is won. Lilithmon says that their alliance will only last until then, which both agree to, each fully intending to betray the other before at that point.
The next morning, Sparrowmon offers to take Taiki to where Nene is being held at the top of the tower, only to be interrupted by Kiriha's arrival with MetalGreymon, Deckerdramon, and Cyberdramon. Kiriha orders his Digimon to attack Taiki, who flees with the other members of Xros Heart. When Kiriha and his Digimon surround them once more, Taiki asks him why he's working for DarkKnightmon before punching him and knocking him to the ground. DarkKnightmon arrives flanked by his undead Digimon and several Guardromon as Kiriha gets up and orders him to finish Xros Heart off. Kiriha appears to follow the order, but instead orders his Digimon to attack DarkKnightmon. The three attack, but the undead Digimon protect DarkKnightmon as Lilithmon arrives with a small army of Tankmon. Lilithmon orders her Tankmon to attack with missiles and DarkKnightmon does the same with the Guardromon. Dorulumon, MetalGreymon, and Cyberdramon deflect the attacks and Taiki DigiXroses Shoutmon into Shoutmon X4, who fights the Tankmon while Kiriha's Digimon deal with the Guardromon.
Taiki and Sparrowmon use the chaos to make their way to the tower to rescue Nene. The two break into the tower and try to convince Nene to leave with them. Nene says that she can't until her brother Yuu is safe from DarkKnightmon. Taiki tells her that unlike Kiriha, who believes that strength is the only way to escape sorrow, he wants to help her deal with her troubles. He offers to help her rescue Yuu, which convinces her to go with him.
Taiki and Nene return to the battle, where Shoutmon X4 and Kiriha's Digimon have made short work of Lilithmon and DarkKnightmon's forces. Taiki DigiXroses Shoutmon X4 with Sparrowmon to form Shoutmon X5, who finishes off the last of the Guardromon with one attack. Lilithmon tries to attack Taiki from behind, but is buried under a pile of garbage by Pinocchimon, who also gives Taiki the Dust Zone's DigiMemory. Taiki uses it to summon MetalGarurumon while Kiriha DigiXroses MetalGreymon with Cyberdramon to create the Cyber Launcher. The two wipe out the remaining Tankmon. With Lilithmon and DarkKnightmon the only ones still standing, Nene asks DarkKnightmon where Yuu is, but DarkKnightmon reveals that thanks to Kiriha, he now has enough dark power that he doesn't need Nene anymore. He takes the dark orb that he'd kept in the tower and uses it to forcibly DigiXros with SkullGreymon and SkullSatamon and immediately turns his newfound power against all present including Lilithmon, who flees from the Dust Zone immediately. Taiki and Kiriha order their Digimon to use their own attacks to deflect DarkKnightmon's, which explodes and obliterates the surrounding area.
In the aftermath of the battle, Taiki and the others dig themselves out of the rubble and find DarkKnightmon to be nowhere in sight. Taiki receives the Dust Zone's Code Crown and encourages Pinocchimon and his crew to make the Dust Zone a more peaceful place. Kiriha tells Taiki that they're back to being enemies and rivals and leaves before Taiki can convince him that they should work together. Meanwhile, Tactimon begins plotting to deal with the holders of the Xros Loaders once and for all as Bagramon descends into his war room as he now considers them to be a significant enough threat to merit his attention.
Tropes:
- Brainwashed and Crazy: Kiriha.
- Casting a Shadow: DarkKnightmon uses a darkness-based attack to level the abandoned factory. After forcibly DigiXrosing with SkullGreymon and SkullSatamon, he uses another one powerful enough that it takes Shoutmon X5, MetalGreymon with the Cyber Launcher, and Deckerdramon to cancel out, which results in a colossal explosion when they do.
- Equippable Ally: Cyberdramon is this to MetalGreymon in the form of the Cyber Launcher. SkullGreymon and SkullSatamon become upgrades to DarkKnightmon's lance and armor respectively. DarkKnightmon also gets SkullSatamon's wings.
- Get a Hold of Yourself, Man!: Taiki snaps Kiriha out of DarkKnightmon's mind control with a punch.
- Macross Missile Massacre: The Tankmon and Guardromon attempt a combine one of these at the orders of Lilithmon and DarkKnightmon respectively, only for their projectiles to be destroyed in midair.
- Non-Fatal Explosions: Both of DarkKnightmon's darkness attacks create massive explosions and neither causes anyone any serious injury. Taiki and friends don't even have to Outrun the Fireball while in the garbage chute.
- Tank Goodness: Deckerdramon makes another appearance. On the villains' side, Lilithmon has a small army of Tankmon to back her up.
- You Have Outlived Your Usefulness: DarkKnightmon pulls this on both Nene and Lilithmon once he has enough power to create the Darkness Loader.
