Task: Question Generation
Input (English): The series is set three years after the events of Digimon Adventure 02, when Digimon who turn rogue by a mysterious infection appear to wreak havoc in the Human World. Tai and the other DigiDestined from the original series reunite with their partners and start fighting back with support from the Japanese government, while Davis, Yolei, Cody and Ken are defeated by a powerful enemy called Alphamon and disappear without a trace. Tai and the others also meet another DigiDestined called Meiko Mochizuki and her partner Meicoomon who become their friends, until Meicoomon turns hostile as well and flees after an encounter with Ken, who reappears suddenly, once again as the Digimon Emperor. The film series also feature several DigiDestined having their partners Digivolve up to the Mega level for the first time, a feat only Tai and Matt had achieved previously.
Output (English): What happened for the first time to the DigiDestined in the film series?