Dunasmon X is an illegally-modified Digimon whom, unlike the X-Program survivors, voluntarily integrated the X-Antibody into his DNA. Integrating the X-Antibody gene triggered an "X-Evolution" which radically mutated his DigiCore and as a result, most of his data was rewritten. Of most X-Antibody mutations, Dunasmon experienced one of the most drastic. The extent of his mutation made no impact on his personality, and is as fiercely loyal to the knight's code as ever; however, the physical changes induced by the X-Evolution drew forth his Wyvern encoding, unleashing power that Dunasmon himself hadn't known existed.

聖騎士“ロイヤルナイツ”の一員だが特異の存在で、忠誠心が強く自らの考える正義に合った主君に絶対的に仕える（それが「悪」と呼ばれる存在であっても）。騎士道・武士道精神が強く礼儀を重んじる。Ｘ-進化により飛竜の能力が引き出され禍々しい姿に変貌、同時に強靱なパワーも獲得した。必殺技：頭部の巨大な角を立てて飛翔し、敵に突進する『ドラゴンズガスト』

| Dunas is short for dunastēs (δυνάστης) (『デュナステース』 Dyunasutēsu), meaning lord.