Brier

Brier, known in the Japanese anime as Kohara, is a Ra Yellow duelist. Brier is a very skilled duelist, but is shy in crowds (stage-fright) and around people. Brier teams up with Beauregard to combat this. Beauregard plays the part of the duelist called "Duel Giant", while Brier gave him instructions via a radio headset during duels. The duo did this to win cards by bullying Obelisk Blue students into unauthorized Ante Duels. Eventually, word gets around to Dr. Crowler who then "hires" Jaden to defeat the "Duel Giant" with hopes that he'll be able to evict him from the academy if he fails. At midnight, Jaden and his friends meet up with the Duel Giant and challenges him to a game. Eventually, he discovers Brier and Beauregard's trick, and convinces the two to battle him out in the open in exchange for not turning them in.

Brier made a cameo in episode 179, watching Jaden's Graduation ceremony.

Deck
When Beauregard and Brier duel alongside each other as the "Duel Giant", they use a Goblin Deck, which includes high-ATK strength creatures such as "Giant Orc" that can have its drawback removed by the Union Monster "Second Goblin". The visual relationship between these cards mirrors their own--a large, powerful being supported by a much smaller one.

When not with Beauregard, Brier appears to play a deck based on the Piercing ability, with cards such as "Mad Sword Beast" and "Fairy Meteor Crush".