D.R. operates as a thief within the setting's main town, serving as a cohort to the master swordsman Cyrano. He actively participates in framing the samurai Ryuma for a stabbing, falsely claiming Ryuma attacked him without provocation as part of Cyrano's broader scheme.

Seven years prior to the main story, D.R. was involved in the "Great Disaster." Alongside Cyrano, he bears responsibility for orchestrating the dragon attack that annihilated Flare's village, killing all inhabitants except Flare, motivated by their group's criminal intentions. Following the attack, D.R. and Cyrano perpetuated a deception, allowing Flare to believe Cyrano heroically saved her from the dragon, masking their true roles in the tragedy. This long-term manipulation forms part of their ongoing criminal activities.

Physically, D.R. possesses ghost-white skin, pointed devil-like ears, and a snake-like tongue, design elements visually emphasizing his antagonistic role. His narrative function is as a secondary antagonist, reinforcing themes of betrayal and exploitation through his actions alongside Cyrano, with no indication of redemption or significant change in his role or motivations.