|“||In order to defeat evil, one must become evil. In a world with the law of the jungle at work, one must rule with power if they wish to accomplish their goals.||„|
|~ The Supreme King|
The Supreme King is one of the main antagonists of the third arc and season of Yu-Gi-Oh! Duel Monsters GX; Dimension World. He is considered one of the darkest characters in the anime, especially due to the fact that he's the dark alter-ego of the main protagonist Judai Yuki. Specifically, he serves as the main antagonist starting in episode 136 until his defeat in episode 143 even then having crucial effects for the rest of the season and early season 4.
In stark contrast to the carefree and compassionate Judai Yuki, the Supreme King is cold, collected and ruthless, willing to sacrifice as many innocent people as he has to in order to complete Super Polymerization. He is also very taciturn; he only talks when necessary or to spite his enemies and when he talks, he speaks in a slightly condescending tone. His demonically golden eyes (and overall visage) show no emotion other than anger and hatred, though he did give a dark chuckle during his duel with Austin. According to Yubel, the Supreme King is an evil power hungry maniac.
Rise of the Supreme King
The Supreme King was first mentioned by Birdman, after the latter was defeated by Judai. Amazed by Judai's courage and equity, Birdman begged Judai to defeat the evil that rules his world (the Supreme King) and to become himself the King.
As Judai went deeper into the alternate dimension, he could not control his emotions, especially anger and hatred, which resulted in the awakening of his dormant powers. When Zure, Knight of Dark World killed a boy who resembled Johan Anderson, a glowing aura appeared around Judai and Zure remarked that he is not like the other duelists. When several of Judai's friends were sacrificed during the Duel with Brron, Mad King of Dark World, Judai let his hatred and anger take control over him which awakened the Supreme King's powers inside himself. Judai used those powers in the duel to get revenge on Brron for the loss of his friends. Although the Duel ended with Judai's victory, his remaining friends were disappointed by his actions and left him alone.
Reign of Terror
After the Duel, the spirit of the Supreme King sensed Judai's negative emotions and tempts him to evil with the Super Fusion card that Brron previously tried to complete. He suggests that to truly defeat evil, Judai himself must become evil. He successfully convinces Judai, and thus became the dominant personality. While in control, his first action was mobilizing an army to slaughter numerous Duelists in order to complete the "Super Polymerization" card. He later began to oppress many local villages, coercing their allegiance through strong-arm tactics and sets his eyes on a village that serves as his primary resistance for a trap for the survivors of his attacks.
After slaughtering a village, the Supreme King was challenged by Jim Crocodile Cook, who was utterly horrified when he saw the dark lord's face. Nevertheless, he Dueled the monarch. In the Duel, he used the Eye of Orichalcum to see the evil inside Judai and tried to destroy it although Professor Cobra's words were stronger than Jim's which was proven once despite the eye's power and reducing the Supreme King's Life Points to 50, Jim eventually lost and was killed by the Supreme King.
Fall of the Supreme King
After Jim's death, the Supreme King focused all his power on eliminating the last pockets of resistance and completing Super Polymerization. But Austin O'Brien arrived and challenged the Supreme King. After a fierce Duel, the Supreme King finally made the winning move, but at the same time, Austin activated an effect from his Volcanic Counter card to ended the Duel in a draw and destroyed the Supreme King once and for all. Using the Eye of Orichalcum, Austin and Jim's spirit rescued Judai and brought him back as the dominant personality. Judai would later use his alter-ego's power against Yubel later in the season after overwhelming his guilt.
Along with Jaden's Elemental Heroes, Supreme King's deck contained dark counterparts known as Evil Heroes. His Dark Fusion fuse his Elemental Heroes cards into an evil version of Elemental Hero fusion monsters (such as Inferno Wing from Flame Wingman, Lightning Golem from Thunder Giant, Infernal Sniper from Rampart Blaster and Wild Cyclone from Wild Wingman). His Evil Hero Malicious Edge is a evil counterpart of Elemental Hero Bladedge. He used Super Polymerization to fuse his monsters with his opponents' monsters.
- Guardian Baou
- Skilled Dark Magician
- Skilled White Magician
- Chaos Sorcerer
- Skull Knight
- Goblin Elite Attack Force
- The Supreme King is similar to Darth Vader from Star Wars: They were heroes turned to the dark side by tragedy, and they also wear black and have yellow eyes. In addition, they will stop at nothing to destroy their enemies and achieve ultimate power.
- In the English version, the Supreme King spoke with a more demonic sounding voice.