Fusion Confusion

'''When two Digimon become one, the DigiDestined encounter a new type of digivolution, and as always, Izzy is ready to explain. Though first, the group must deal with the time bomb that is Ken's old base.

Synopsis
Rushing into the base while Paildramon battles Okuwamon, they reach the center of the base and Ken puts his Crest in. But the reactor isn’t stabilized! They follow the pipes into the reactor where they find a stream of darkness. The base is about to explode when Paildramon rushes in and disposes of the base, and the base with it. Then Izzy explains to them how DNA Digivolving works and it took place before and why the older kids' Digimon can’t Digivolve to Ultimate any more.

Digivolutions
(Number indicates order of occurrence.)