Armageddemon

Armageddemon is an Unidentified Digimon whose name is derived from Armageddon, the location of the final battle between good and evil prophesied in the Bible. Armageddemon was created when an enormous number of Kuramon fused into a giant Digi-Egg. It is a brutal Digimon whose power far surpasses Diaboromon's and even Omnimon's.

Digimon World 3
Armageddemon appears in the opening video, and can be fought near the end of the game. Excluding five rare Digimon cards Armageddemon is the second strongest Digimon card after Imperialdramon Paladin Mode. Armageddemon is a black Mega Digimon card that has 65/62.

Digital Monsters: D-Project
Armageddemon digivolves from MetalTyrannomon.

Digimon World DS
Armageddemon appears as a boss which makes up 2 zones, guarding the warp to the final boss, Chronomon Destroyer Mode.

Digimon World Dawn/Dusk
Armageddemon is obtainable through DNA Digivolution of Diaboromon and Infermon, but you must also have a Kuramon in your party. You also have to have them both level 81 or higher, and a defense that is 480 or higher. It is the strongest Digimon that is found in the wild in Dusk.

 Attacks
 * Destiny Destroyer (Ultimate Flare): Fires a solar-hot energy blast from his mouth.
 * Full Scale Attack (Black Rain): Launches a swarm of missile-like projectiles from his back.