Duval is a colossal figure who was first seen wearing a medieval-style mask. Standing at about two and a half times the height of an average person, he has a muscular torso but relatively slender arms and legs. His head and shoulders are clad in armor, while the rest of his attire includes an open leather jacket, black pants, cowboy boots, and a long fur cape.
Beneath his iron mask, Duval bears a striking resemblance to Sanji's poorly drawn wanted poster, with the only difference being his eyebrow, which curls downward instead of upward like Sanji's. This uncanny similarity caused him significant trouble with marines and bounty hunters, forcing him to hide his face for protection. Despite numerous injuries sustained as a result, the most painful one is a scar on his back.
Seeking revenge against Sanji, Duval confronted him, only to have his facial structure completely altered by Sanji's powerful kicks. The brutal yet effective transformation resulted in a handsome new face entirely different from his original appearance. Delighted with his new look, Duval enjoys the benefits it brings, although he struggles with winking, often failing to coordinate both eyes simultaneously.
