Dimentio

Master of dimensions.
Dimentio
Debut	Super Paper Mario

One of Count Bleck's minions, Dimentio has access to dimensions of every kind and wields magical bursts of energy. He can also create duplicates of himself and teleport at will. He is only fought twice (technically three times) in the game, but is a guiding force behind a few other battles.

Backstory

Like O'Chunks and Mimi, Dimentio heard that Bleck's intention was to destroy all of the imperfect worlds and create a new world in their place. Unlike the others, Dimentio realized that Bleck was lying and planned to leave everything in ruins as vengeance for the fate of his beloved. He forced himself into Bleck's group despite multiple refusals for the sole purpose of learning how to stop him. Prior to the final battle, he appears to be the only character who realizes that Mr. L is Luigi.

Mario first encounters Dimentio in the Yold Ruins, where the jester uses his magic to turn Fracktail against the hero. Having confirmed for himself that Mario was the legendary hero from the Prognosticus, Dimentio began to subtly help Mario by sending Peach his way and testing his strength.

Mario and co. have a proper battle against Dimentio in the Dotwood Tree, where he teleports them to a dimension where he is 256 times stronger. Fortunately, so are the rest of the group. He returns during Chapter 5 to test them again, this time with O'Chunks's (unwitting) help. By planting a Floro Sprout in O'Chunks's subconscious, Dimentio makes him somewhat stronger, but still beatable.

Prior to Chapter 6, Dimentio begins to turn on Bleck by tricking Mimi and Mr. L into disobeying orders and attacking Mario and co. He later catches up to Mr. L and sends him to the Underwhere to be reunited with Mario and co. later. He then sends the main group to the Underwhere so that they can revive a dead Pure Heart.

Dimentio is not seen again until Mario and Luigi reach Castle Bleck's interior. On their way to the final battle, he and his duplicates attack them from behind mirrors. When the brothers meet him in person, he leads them on a chase through all of the previous worlds, then explains his true intentions to overthrow Bleck and create a world devoted to himself. When the Mario Bros. refuse to help him, he attacks Luigi in a one-on-one battle while Mario continues toward Bleck.

Super Dimentio

After Luigi defeats Dimentio, the jester traps them both in a box and pretends to sacrifice himself to prevent Luigi from fulfilling his part in the Dark Prognosticus. In truth, he only knocks Luigi unconscious and plants him with a Floro Sprout.

Once the group has defeated Bleck, Dimentio arrives to finish the count off, but is foiled by Nastasia. Dimentio then grabs the Chaos Heart and, controlling Luigi via the Floro Sprout, uses it to turn him into a monster. Dimentio himself merges with the creature to create Super Dimentio. He attempts to kill Mario and co., as they have served their purpose to him, but Tippi shows up with the Pure Hearts to weaken him. The group kills him and saves Luigi, but Dimentio leaves enough of himself behind to continue controlling the Chaos Heart. It is only overcome by Tippi and Bleck's love for each other.