Tai and Agumon continue on their journey separate from the other DigiDestined when they find themselves surrounded by Giromon after rescuing a Cutemon from them. Just as it appears that MetalGreymon will have to fight the Giromon, the battle is joined by the deadly Rebellimon, who easily tears through the Giromon until only one is left, which flees for its life when Rebellimon fires his machine guns at it, before Rebellimon turns his attention to MetalGreymon who holds his own against Rebellimon. However, Rebellimon suddenly has a memory flash of Ogremon fighting Greymon which causes him to call off the fight, asking that they stay away from him before he departs. Cutemon takes Tai and Agumon back to his home before explaining recent events in the region regarding bad Digimon, turf wars, and then Rebellimon arriving to challenge powerful Digimon to combat, and still fighting even after he is beaten.
Soon, Rebellimon is challenged by the surviving Giromon, having brought several Boarmon to attack Rebellimon, only for Tai and Greymon to arrive to assist. When one Boarmon corners Tai, Greymon overpowers the one that pinned him and takes it out before dealing with the one that threatened Tai with a well-timed Nova Blast. When all the Boarmon are deleted, the Giromon flees once more. Cutemon heals Agumon's injury, before Tai inquires as to if Rebellimon has a reason for his fighting. However, they are soon engaged by the very same Boltmon that defeated Rebellimon previously. Due to being a Mega Digimon, Boltmon easily overpowers Rebellimon with little trouble, before moving in to finish him off, even as Cutemon tries to protect him. When Cutemon is about to be crushed by Boltmon's foot, Rebellimon recovers and saves him, and when Cutemon is able to heal Rebellimon's injuries, he is able to fight back against Boltmon, using a missile to stun Boltmon so he is struck by his own axe flying back at him, slicing his chest open to expose his core, before Rebellimon then uses his fist to destroy Boltmon's arm, then his core, defeating and deleting the Mega.
Afterwards, Rebellimon decides to take his leave, but asks Cutemon to join him. After they depart, Tai and Agumon realize that he might be the same Ogremon that they had met previously due to Rebellimon stating that he will be going "straight ahead," Ogremon's last words to them, but they believe that it couldn't be. However, the metal ring on Rebellimon's horn indicates that it is true along with Rebellimon's earlier flash of Ogremon fighting Greymon.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonist(s), and italicized characters feature non-explicitly, e.g. voice, silhouette, image.)