Chaos Heart

The Chaos Heart is a dark source of power from Super Paper Mario. It looks like a giant Pure Heart colored gray and black. As prophesised in the Dark Prognosticus, the Chaos Heart was unleashed by the marriage of a powerful king and a pure princess, and used to create an interdimensional rift known as The Void, which would engulf the universe. The Chao Heart can only be destroyed by killing either the controller, or by another marriage like the one the created it, although that one must have true love. The Chaos Heart makes the controller invincible, so without the Pure Hearts to counter its power, defeating a controller of the Chaos Heart is impossible.

The Chaos Heart was first controlled by Count Bleck, who wanted to destroy all worlds and create new ones out of inconsolable heartbreak due to the disappearence of his love, Lady Timpani. The Chaos Heart would soon be overridden and banished by the power of the Pure Hearts, closing The Void and saving the universe from destruction.

After the four heroes defeat Count Bleck, Dimentio appears and takes control of the Chaos Heart. Having brainwashed Luigi earlier, the two of them merge with the Chaos Heart in order to form Super Dimentio. Luigi was the ideal host for the Chaos Heart, so the Chaos Heart's power was magnified to proportions far larger than its power when Count Bleck wielded it. However, in the end, it is still defeated by the power of the Pure Hearts and the three remaining heroes.