Ridley Sheldon

Sheldon is eccentric, theatrical and obsessively devoted to his dolls. He treats them with an attachment that unsettles other characters, particularly when he uses life-sized puppets to impersonate real people.

He is also a calculating gamer. Sheldon does not rely only on cards; he constructs environments that alter the conditions of play and deliberately withholds information about those advantages from his opponent.

His attachment to Fiona is particularly intense. The doll is more than decoration to him, and damage to it affects him far more strongly than an ordinary loss.

Sheldon is an experienced game specialist and Duel Monsters player. During his first encounter with Yugi, he remotely operates a nurse puppet and defeats him, taking Yugi's Neon Knight card as his prize.

His later arena creates a "doll field" effect. Monsters manifested within the doll house acquire doll-like bodies, making them unusually resistant to conventional destruction and giving Sheldon a substantial environmental advantage.

Sheldon uses monsters including Gargoyle, King Beetle and Salamandra. He also incorporates the captured Neon Knight into his cards after defeating Yugi.

Sheldon is introduced when Kaiba activates the Four Game Masters as part of his continuing effort to defeat Yugi. Sheldon serves as the first member of the group to confront him.

Disguising a puppet as the school nurse, Sheldon defeats Yugi and takes Neon Knight. Kaiba later arranges for Yugi to be brought to Sheldon for another confrontation inside the specialized doll-house arena.

Dark Yugi identifies the secret behind Sheldon's doll field and uses Death Wolf's howl to destroy the dolls indirectly. Sheldon loses the rematch, allowing Yugi to reclaim his card.

Afterward, Sheldon wanders through the rain clutching Fiona after the doll's face is cracked during the confrontation.

Seto Kaiba employs Sheldon as one of his Four Game Masters. Sheldon participates in Seto Kaiba's plan to challenge Yugi Mutou through specialized games.

Yugi Mutou is Sheldon's principal opponent. Sheldon initially defeats Yugi Mutou through his nurse puppet, but Dark Yugi later discovers the weakness of Sheldon's doll-house game and defeats him in their rematch.

Ryuichi Fuwa, Aileen Rao and Daimon are Sheldon's fellow Four Game Masters, each possessing a different gaming specialty.