WarGreymon

WarGreymon is a mega level Digimon that is very powerfull, one of the strongest Digimon ever. It's impossible for any level of Digimon to defeat it besides other Mega Digimon. It usually digivolves from MetalGreymon and it could digivolve into the even more powerful Omnimon (which is still considered an Mega) if he's DNA digivovled with MetalGarurumon.

Digimon Battle Spirit
In both Digimon Battle Spirit and its Digimon Battle Spirit 2, Agumon can warp digivolve to WarGreymon

Digimon Rumble Arena 2
If Agumon warp digivolves or MetalGreymon digivolves like normal, the player can be WarGreymon

Digimon World DS
WarGreymon digivolves from MetalGreymon at Level 47 and Friendship 90%. He also appears when a Digivolve disk is used on a Dragon Digimon, and attacks with Great Tornado.

Digimon World Dawn & Dusk
WarGreymon Digivolves from MetalGreymon at level 52 and Friendship 90%, if the player has already befriended Agumon. He can DNA Digivolve with MetalGarurumon to become Omnimon. In Dawn, he is a salesman at the Shine N Route.

Attacks
 Attacks In Rumble Arena 2 
 * Terra Force (Gaia Force): Gathers all of the energy within the atmosphere and concentrates it into one spot, then fires it as an extremely dense, high-temperature fireball energy shot.
 * Great Tornado: Spins at tremendous speed like a tornado and launches itself at the enemy.
 * Brave Shield: Uses its "Brave Shield" to defend.
 * Mega Claw (Dramon Killer): Slashes its "Dramon Killer" gauntlets.
 * Dragon Killer
 * War Driver: Builds up energy in its claws and strikes the enemy down with them.
 * Ultra Tornado (Grey Fire): Wraps itself in a giant tornado of flames, sending smaller tornadoes outwards at enemies.