The Ultimate Clash

The Ultimate Clash is the forty-fifth episode of Season 1 in Digimon Adventure, and the forty-fifth  episode overall.

Synopsis
Tai and WarGreymon start to fight Matt and MetalGarurumon. Nobody can stop them since they're Mega Level Digimon. A weird light possesses Kari's body and explains everyone why they are here and the history of the Digivices.