Kurosaki Matomiya is the partner of agumon. After he found out how to control the dark digivolution shown the way by the digi-elf, his agumon digivolves to SkullGreymon:Tame mode. Later it is digivolving further into DarkWargreymon.
Digimon World: V-X
After kurosaki encounter a group of terrorist organization black oath's thugs who are trying to perform detonating the bomb which they so called Amaterasue Sigma that could destroy the entire Yamato server, he face them alone seems he had no choice. But his Greymon is stopped by the BlackWargrowlmon from the leader of those thugs called Richard Gale. The thugs leader tries to take out both of their lives and richard torture kurosaki before delete them. After seeing that, Greymon's anger causes him to digivolve into SkullGreymon which turns to kill Kurosaki after defeating BK Wargrowlmon, WaruSeadramon and MetalTyrannomon. Before SkullGreymon could kill Kurosaki, the mysterious Digi-Elf arrives in scene, performing Digi-Seal and De-Digivolve to Agumon.
The Tame Mode:
DIgi_elf who they had been rescued takes them to the place where they could learn the legendary secret taming techniques. Kurosaki asked DIgi-ELf if agumon could digivolove to MetalGreymon but upset by the words of Digi-Elf. The digi-elf tells him about one of the legendary secret taming techniques called control module.