Ryudamon is a Dragon Digimon and a carrier of the X Antibody whose name and design are derived from the Promoted Rook (竜王 Ryū-ou?, lit. "Dragon King") chess piece. Because it has an old-style interface on its brow, it has been conjectured to be an experimental "Prototype Digimon" from before Digimon were discovered. Although its body is clad in Japanese-style armor high in defensive ability, its movements are nimble, so it fights by resolutely leaping into the opponent's chest. It studies the business of combat so that it is strong enough to fight, and possesses Bushikatagi, with bravery and a soul that doesn't fear more powerful Digimon. The data that is said to have been hidden within the deepest parts of its DigiCore, during an experiment, is the ferocious combat data of the "Dragons" and "Generals" of Japanese mythology, and it is said it has the potential to grow into a mighty Digimon.
- Kabutogaeshi (兜返し? lit. "Helmet Reversal"): Withstands the opponent's attacks with its armor and helmet, then counterattacks.
- Katana Attack (居合刃 Iaijin?, lit. "Iai Blade"): Leaps into the opponent's chest and fires a blade of iron from its mouth.
- TERA BURST: Blasts the opponent with multiple explosions.