Apocalymon

Apocalymon is the main and final antagonist of Digimon Adventure. He is Mega Digimon.

Digimon Adventure
In Now Apocalymon,

In The Fate of Two Worlds,

Attacks
River of Power (MetalSeadramon)

Crimson Lightning (Myotismon)

Giga Cannon (Machinedramon)

Reverse Digivolve

Death Claw

Virus Grenades

Total Annihilation

Trivia

 * Apocalymon's name comes from the word "apocalypse" which is synonymous with the end of the world.
 * Apocalymon's design is often speculated by fans to be based on Winslow Leech from the 1974 film Phantom of the Paradise.