Yu-Gi-Oh! Capsule Monsters

Red-Eyes Black Curse (1x7)

:

They group arrives in a volcanic region, where they must get rid of the Sword of Chaos. Tristan fains Thunder Dragon. Joey ends up merging with Red-Eyes Black Dragon, becoming evil; however, he's fighting internal for control of his body. He succeeds with the Pharaoh's help, finding that the sword they need to get rid of its not the one on top of the volcano, but in Red Eyes. Once removed, the dragon becomes one of Joey's capsule monsters.