Alphamon

Alphamon is the Mega form of Dorumon, a Digimon of great power of the Alpha-Gain-Force. He is not just one of the 13 Royal Knights, but also their leader of legend, destined to rule them, yet condemned to be the "Lord of the Empty Seat," forever-absent. Alphamon is allso the only member of the knights who has his x-antibody form the satrt, not beiing given or taken from a digimon.

Abilities
Digitalize of Soul, Great Dragon's Ultimate Vanguard Sword

Digimon X-Evolution
When attacked by Omnimon, Dorugremon digivolve into Alphamon, regaining his memories. Omnimon immediately sided with Alphamon and took him to see Yggdrasil. But they faced Death-X-Dorughoramon, whom Alphamon managed to drive away before he entered Yggdrasil’s inner sanctum to destroy it, but DeathXmon appeared and a violent battle began. Powering up to Ouryuuken mode, Alphamon attacked DeathXMon - but he felt all attack he inflincts on DeathXmon.

This caused Alphamon to realized thar DeathXmon was his "other half", created from the data Yggdrasil removed from Dorugamon's body. Knowing this he hurling his blade in a boomerang arc and grabs DeathXmon as the blade return, implaing them both. Alphamon transferred his X-Antibody to Omnimon before merging with Death-X-Mon and regressing back to Dorumon.