|Human Partner||Musha Yuuji|
Alphamon: Ouryuken (with DORUmon)
The two first met in the Ulud Terminal, and Yuuji foolishly had Ryūdamon attack Ultimate Brachiomon as a Child. The ensuing fight nearly killed Ryūdamon, and the two were only rescued by Metal Garurumon (X-Antibody), a Digimon that was leading a rebellion against the forces of Yggdrasill.
Later, when the two of them met Kouta and DORUgamon, Yuuji criticized Kouta for using the XAI system to make reckless but powerful attacks. Upon re-encountering Ultimate Brachiomon, however, Yuuji had no choice but to use the XAI system to defeat it in one hit.
Later, the two tamers and their partners confront Death-X-mon, a deadly being born from DORUmon's X-Antibody. Ryūdamon, having evolved into Ouryumon, sacrifices itself to save Alphamon's life, leaving behind a sword that allows Alphamon to become Alphamon: Ouryuken and save the New Digital World.
Ryūdamon appears as Ouryumon, having inexplicably been resurrected. Ouryumon, along with Yuuji, Alphamon, and Kouta helps Yggdrasill raise an army to defeat the Seven Great Demon Lords.