The Blade of Chaos is a cursed sword featured in the seventh episode of Yu-Gi-Oh! Capsule Monsters. It is the object that the third trial is centered around, but unlike most other items, there are two versions: a decoy embedded within a volcano, and a real one embedded within the back of "Red-Eyes B. Dragon". While embedded within "Red-Eyes", it forcibly caused Joey Wheeler (whom was clinging onto Red-Eyes' back at the time) to merge with him into a dark warrior, in a similar fashion to Yugi Muto using the Duel Armor to merge with his monsters, but unlike Yugi, Joey was possessed by the evil curse of the sword, and aggressively turned on his friends. Eventually, during his fight with Yugi, Joey managed to regain some control of himself in order to enable Yugi to blast him with Dark Magician's "Dark Magic Attack" and cause Joey and "Red-Eyes" to split apart. Afterwards, Joey revealed that the real "Blade of Chaos" was embedded in the back of "Red-Eyes" (as by that time, the decoy had sunk into the volcano), removed it and allowed Yugi to destroy it so they could clear the third trial.