Edo Pheonix's legal guardian and champion of the Pro League. When Edo was a child DD made a promise to remain the champion until Edo was old enough to duel in the league, which he was able to keep for 10 years.
It was revealed that in the past DD broke into Edo's father's home to steal a Destiny Hero card and then, having been possessed by the Light of Destruction, murdered his father. DD kept this hidden from Edo for the 10 years he raised him, having only used the stolen cards in underground matches.
DD stated he only became Edo's guardian to avoid detection in investigations relating to his father's murder.