The Chaos Heart is a dark source of power from Super Paper Mario. It is a large Pure Heart-like object colored gray and black, constantly releasing near-invisible waves from itself. After Luigi stomps on it during the opening, the Chaos Heart briefly emits a dark, star-like aura (seen on the right); it is implied to be a brief moment of instability that throws everyone in attendance across Castle Bleck.
As written in the Dark Prognosticus, the Chaos Heart was unleashed by the marriage of a furious monster king and a fair and lovely princess. Once summoned, it created an interdimensional rift known as The Void, which would eventually engulf all dimensions. The Chaos Heart can only be destroyed by either killing the controller, or with the concentrated power of love embodied by the Purity Heart. As the Chaos Heart empowers its controller to the point of invincibility, the Pure Hearts are necessary to overcome it.
The Chaos Heart was first controlled by Count Bleck, who wanted to destroy all worlds and supposedly create new ones due to the disappearance of his love, Lady Timpani. Unbeknownst to his minions, however, Bleck had no intention of remaking the universe; his final goal was to perish along with the rest of creation (a fact he kept secret from his subordinates in order to preserve their hope). In response, Merlon gathers four heroes to collect the Pure Hearts and defeat Count Bleck, which they eventually accomplish by using the Pure Hearts to destroy the impenetrable barrier protecting Count Bleck.
However, despite Count Bleck's defeat, the Chaos Heart remained active. At this point, Dimentio appeared and revealed that he had taken control of the Chaos Heart, planning to use its power to remake the universe in his image. Along with a brainwashed Luigi, Dimentio merges with the Chaos Heart in order to form Super Dimentio - since Luigi was the ideal host for the Chaos Heart, its power was magnified to far greater proportions than the power Count Bleck had wielded. As he shrugged off the heroes' attacks, Super Dimentio used his new powers to accelerate The Void's expansion, rapidly consuming all worlds.
Unfortunately for Dimentio, Count Bleck is able to recreate the Pure Hearts through his love for Tippi - revealed to be Lady Timpani in a new form - and his loyal minions. The three remaining heroes use the Pure Hearts to negate much of Super Dimentio's Chaos Heart-derived power, allowing them to defeat him and free Luigi. Although Dimentio expires soon after, his last act is to imbue a "shadow of his power" into the Chaos Heart, preventing it from disappearing long enough to complete the destruction of the universe.
To stop the cataclysm once and for all, Count Bleck and Tippi return to Castle Bleck's chapel, the very spot where the former first created the Chaos Heart. With the dark artifact floating between them, the long-lost lovers finally exchanged vows, reforming the Pure Hearts one last time. As Count Bleck and Tippi reaffirmed their everlasting love for each other, the Pure Hearts encircled the Chaos Heart and united into the Purity Heart, resulting in the annihilation of the Chaos Heart, the sealing of The Void, and the return of all the dimensions it destroyed.
Names in other languages