Dimentio
Dimentio is a major antagonist in the game Super Paper Mario. Initially a minion of Count Bleck, Dimentio is a powerful magician capable of several feats, such as teleportation, invisibility, and mind-control. Like Mario, he has the power to flip between dimensions, and is control of a dimension of his own, Dimension D.
Dimentio originally followed the orders of Count Bleck to stop Mario and his friends, but soon after Dimentio decided to "help" them along instead. His plan was to have Mario bring down Count Bleck so he could gain control of the Chaos Heart to destroy all worlds and create perfect ones.
Dimentio used his mind-control powers to gain the support of Luigi and use the Chaos Heart to its full potential, transforming himself into Super Dimentio. His plan fell short when Tippi used the Pure Hearts against him and cut off his power from the Chaos Heart, allowing him to be defeated by Mario.