While the DigiDestined rebuild the Digital World, Davis, Yolei, and Cody unlock normal Digivolution. At the same, they ally themselves with a reformed Ken, who joins the team to fight Arukenimon, a Digimon who revives the Control Spires as other Digimon. When the Control Spire Digimon prove to be stronger than them, the DigiDestined learn DNA Digivolution, which enable two champion-level Digimon to merge into a stronger ultimate-level one. When Arukenimon creates BlackWarGreymon, he begins to destroy each Destiny Stones, hoping to fight Azulongmon, who appears when each Stone is destroyed. After BlackWarGreymon flees, Azulongmon warns the DigiDestined about an impending threat behind Arukenimon and Mummymon.