S1·E13 The Rise of RiseGreymon

Merukimon appears in the real world to prevent Falcomon from being defeated, defeating easily the DATS Digimon and reverting Biyomon to a Digi-egg in the process. In a desperate attempt to find his way back to Kristy after Merukimon revives him, Biyomon loses control and quickly evolves to Aquilamon and then into Garudamon, wreaking chaos over the city. The DATS and their Digimon feel helpless before the overwhelming power of the Ultimate Digimon. Frustrated at not being strong enough to protect the smiling faces of both his family and friends, Marcus lets out a cry that awakens the birth of a new DNA Charge that allows GeoGreymon to digivolve into his Ultimate form, RizeGreymon.