Dimentio is a villain in Super Paper Mario. His name is a pun on dementia and dimension. Like Mario and Mimi, he can flip between dimensions, but he can also manipulate them (an ability he shares with Merloo) and controls Dimension D, which he designed. Skilled in duplication, teleportation, and invisibility, Dimentio is one of the four main minions of Count Bleck, along with O'Chunks, Mimi, and Nastasia. However, over the course of the game, Dimentio rapidly reveals himself to be the true main antagonist, using his 'master' merely as a way to further his plans to obtain the Chaos Heart and use its power for his own agenda.
Not much is known about Dimentio's past other than that he is a freelance mercenary whom Count Bleck hired, probably for his dimensional skills; other early life information on the magician is limited and contradictory. One of Carson's stories implies that Dimentio may be the descendant of the magician who created the Pixls. However, it is also implied that he wrote the Dark Prognosticus, which was the book that inspired the creation of the Pixls. Regardless of his exact role in the creation of the Prognosticus, Dimentio quickly became involved in Bleck's attempt to fulfill it, if only for his own ends.