Dorumon (nicknamed X) is the most potential protagonist and partner of Daiki. He was once as the member of the Dark Kings until he betrayed them because of Chronomon Dark using them for evil.
He is the Rookie form of DexDorugoramon due to his evolution failure process. He was found by Daiki and the others when they got in the Digital World.
The Champion form of Dorumon achieved from Daiki's courage.
The alternate Ultimate form of Dorumon.
The Ultimate form of Dorumon achieved from his full power or activates Crest Mark of Dragon.
The Mega form of Dorumon before his evolution failure begins to revert back to Dorumon.
The secondary Mega form of Dorumon.