BlackGreymon

BlackGreymon is a viral Greymon, more blue than actually black.

Digimon World Data Squad
Greymon (Blue) is an unlockable digivolution in Biyomon's galaxy. He also apears as an enemy in some zones.

Digimon D-Project
A bluish virus version of Greymon can be seen on the Digimon Dictionary.

Digimon Rumble Arena 2
BlackGreymon is the digivolution of BlackAgumon, and can warp digivolve into BlackWarGreymon.

Attacks
 * Nova Blast (Mega Flame)
 * Great Horns Attack (Great Antler)
 * Grey Tooth