Duark is a Darkus Bakugan who considers himself the Ultimate Bakugan. He can change his attribute to any he wants and he can use all attributes at the same time. He is Kurai's Guardian Bakugan.
- Attribute: Darkus
- Power: 800Gs
- Battle Gear: ?
- Owner: Kurai
After a battle with Hydranoid and Alice, Duark evolved into Chaotic Duark (though he was only seen in ball form and briefly in bakugan form and his abilities were never seen in action).
He is very simialar to somewhat a dragon. He can shoot dark energy from his mouth, eyes, and tail. He is one of the most powerful bakugan. He can defeat almost all the bakugan easy. He is very aggresive and will always try to win no matter if the battle is over. He fears nothing. Not even Fear. He sometimes makes bakugan fear so bad, they lose all there Gs.
- Chaos of Darkness: Nullifies opponents abilities and transferrs 500Gs to from the opponent to Duark
- Laser Darkus: Drains 450Gs from the opponent
- Massive Combustion (Pyrus Ability): Adds 700Gs from the opponent to Duark
- Tsunami Waves (Aquos Ability): Transfers 400Gs from the opponent to Duark\
- The Light (Haos Ability): Adds 200Gs to Duark
- Avalanche Earthquake (Subterra Ability): Drains 300Gs from opponent
- Silent Winds (Ventus Ability): Transfers 150Gs from opponent to Duark
- Violent Attributes (All Attributes): Adds 1000Gs to Duark
- Ultimate Bakugan: Drains opponent by 400Gs and Adds 1000Gs to Duark