MedievalDukemon is a Warrior Digimon and a carrier of the X Antibody whose name and design are derived from "Medieval Dukemon". In "Witchelny", it is praised as the "Legendary Hero", as it suddenly appeared and drove out the foreign invaders in ancient times, and although it's not certain, it is said that it transcends time and is still in existence. It battles using armor made by Sorcery, it holds the alias of "Whirlwind General" due to it governing the "Vortex Warriors", and it possesses the mightiest magical lance, "Dynas", which conceals the power of the wyvern. Although there are almost none who have seen its form in the "Digital World", it is called the "Warrior of Fantasy" there, as gaudy ornamentation is applied to the armor over its whole body, and a coat of arms is affixed to its solemn form.
MedievalDukemon is the first form of Duke, one of the Holy Knights who can restore Dragon Spirits. MameTyramon is his servant. When asked, he refuses to give the Dragon Spirit to save Grademon and instead challenges them to battle. Though seemingly defeated, he proceeds to kill Grademon and then implant the Dragon Spirit, revealing that to restore the Dragon Spirit, the Digimon needed to be near-death. When he senses trouble, he digivolves to Gallantmon X and sends the group on their way.
- Rage of Wyvern: Fires an attack from Dynas.
- Final Crest