Digimon: Digital Monsters - Season 2 - Eps 44: Dark Sun, Dark Spore
Ken meets Yukio Oikawa, who knows his past and wants to copy the data of the Dark Spore embedded in his neck for the kidnapped children. The rest of the DigiDestined fight LadyDevimon and MarineDevimon to catch up to him. Yolei and Cody are both forced to watch their Digimon partners kill other Digimon.
About Digimon: Digital Monsters

Title: Digimon: Digital Monsters
First Air Date: 1999-03-07
Last Air Date: 2001-03-25
Status: Ended
Rating: 8.1/10 (from 845 votes)
Language: JA
Seasons: 2
Total Episodes: 104
Network: Fuji TV
Genres: Animation, Action & Adventure, Sci-Fi & Fantasy, Kids
Production Companies: Toei Animation, Toei Company
Synopsis
While at summer camp, seven kids are transported to a strange digital world. In this new world they make friends with creatures that call themselves Digimon who were born to defend their world from various evil forces.
Cast

Reiko Kiuchi
Daisuke Motomiya (voice)

Megumi Urawa
Iori Hida / Armadimon (voice)

Rio Natsuki
Miyako Inoue (voice)

Hiroaki Hirata
Takeru Takaishi (voice)

Romi Park
Ken Ichijouji / Digimon Kaiser (voice)

Junko Noda
V-mon (voice)

Kae Araki
Hikari Yagami (voice)

Koichi Tochika
Hawkmon (voice)

Miwa Matsumoto
Patamon (voice)

Naozumi Takahashi
Wormmon (voice)