Brron Mad King of Dark World is the first main antagonist in the Dark World arc of Yu-Gi-Oh! GX in season 3. Though merely in two episodes and occasional flashbacks, the series takes full turn for darker themes once Brron takes action.
He was voiced by Kentarou Itou in the Japanese version, and by Jamie McGonnigal in the English version.
Brron is a tall, slender humanoid with chains wrapped onto him, and bones for hair.
Brron in the Leader of the Dark World Army. After Zure, Knight of Dark World, his right hand man was defeated by Jaden, Brron challenged Jaden the next day. During the duel Brron mentioned that Brron captured most of Jaden's friends and that all of them have been marked by a certain symbol. To assure victory and to break Jaden's mind he activated four Wicked Doctrine Spell cards. Doing so, Chazz, Alexis, Atticus and Hassleberry got sacrificed. Syrus was the only one to survive. Doing so Jaden was in rage and started to become the Supreme King. After Brron was defeated, he mentioned that he was just a pawn and that Yubel was the true being responsible for everything that's happened. He also mentioned that Jesse, Jaden's friend, was with the stars, not before Brron disappeared as well laughing having infuriated his winning opponent who fell to evil, realized presumed dead Professor Viper's words were true and destroyed two more of his friends, returning in trauma with his six friends vanishing.
Brron's deck is a Dark World Deck. His strongest monster that was summoned was Reign-Beaux, Overlord of Dark World, however Brron mention he has a monster that was practically unstoppable called; Colorless, Chaos King of Dark World. But Brron never got the chance to summon his monster since he was defeated.