Dimentio is the true main antagonist of Super Paper Mario. He is the son of a magician and the brother of Shadow.
Backstory[]
Prior to the events of Super Paper Mario, Dimentio actually had gone through a lot. There was a magician that created the Pixls around 3,000 years ago. That was his obligation. This magician's secret, however, was a darker one. He didn't just poof the Pixls from thin air. He took the souls of the dead and placed them within Pixl vessels that he created. Basically, whoever died, and became a ghost, he stole their soul and put it inside of the Pixls. This is how they were sentient and mindful. When put inside of the Pixl, the victim retained no memory of their past life, and was thus, completely obedient towards the magician. This magician was part of the Tribe of Ancients, and had a family. However, there was only one bloodline of magicians within the Tribe of Ancients. Thus, there was only one long line of magicians part of one family. To assist in figuring out who this magician was, there was also a being named "Shadoo," the mysterious being that copied Mario and his party's abilities and created shadows of them. Shadoo says that it works for the Ancients, which was actually a lie to get the Heroes of Light to assist it. Shadoo was created by the Ancients, but resents them to no end. It is never reavealed precisely why Shadoo hates the Ancients, but... the stories seem to imply why Shadoo hates them. You see, Shadoo is called out for its illusory powers. It was created by the Ancients, right? And it hates them, right? Well, this is VERY similar to the Pixl Queen. The Pixl Queen was another Pixl, like the rest of the Pixls. However, it was presumed that it was a demon, due to just how outright evil it was. It led a revolt, taking control of all Pixls, and battled against the Ancients in a war,Dimentio's sister is Shadoo. Or more so, his sister's soul, which their father put into the Pixl Queen. Dimentio was the author of the Dark Prognosticus, and his father received the book after having thought his son died. After his daughter perished after the incident, he found a job, and the first person he desired to be alive again was his daughter. This is also supported by how Tippi seems to have recognized Dimentio, which furthers his connection to the Ancients.
With all this considered, Dimentio's father was a murderous psycho, and his mother had died in an accident that Dimentio managed to endure. His sister passed of a disease, and his father passed of old age. Dimentio was the last magician left. These are the events that took place in Dimentio's history before the events of Super Paper Mario unfolded.
Very early on within the story, Dimentio approached Count Bleck himself, and wanted to join his cause. This was Dimentio's objective, as he is a mercenary. The count turned him away however, until he read about someone who played a very vital role in the Dark Prognosticus. So, the count brought Dimentio on board. This foreshadowed what Dimentio actually was, and what role he would play.
Dimentio is first seen in the beginning of the game during the first meeting Count Bleck held--alongside Mimi, O'Chunks and Nastasia, of course. He doesn't contribute to the conversation outside of embarrassing Mimi, but is intrigued when Nastasia brings up that the potential hero of prophecy--Mario--was heading their way. Dimentio heads to Yold Desert with O'Chunks to see this hero himself, and meets him first when encountering Fracktail, the robotic guardian of the second Pure Heart. He uses his magic to drive Fracktail insane, turning him against Mario. After Mario destroys Fracktail--stripping the guardian to bones unintentionally, Dimentio realizes that he may well be the hero of prophecy, and initiates a secret plan. He comes to knowledge that the prophecy tells of four heroes, and determines that Peach--involved in the creation of the Chaos Heart--must be one of the heroes, and saves her from certain brainwashing. He likely does something similar to Bowser, who awakens in Bitlands with some of his minions. But that was, unfortunately, never explicitly stated nor shown. Dimentio is then ordered to destroy the heroes. He sympathizes with Mario, revealing himself, at first, to be a kind-hearted and gentle villain. He does battle with Mario, losing, and then decides to... "help" the heroes. Dimentio tests their power, and deems them ineligible. So, he decides he must train them more.
He returns to Castle Bleck to eavesdrop on a conversation between Bleck and Nastasia--saying they have such DEEP conversations--and then he travels to The Land of the Cragnons to meet an "acquaintance," most likely King Croacus IV, to obtain functional Floro Sprouts. He then tests them later by modifying and brainwashing O'Chunks to do his bidding. He finds that the heroes are coming along nicely, after they defeated his modified O'Chunks so easily. And when he taunts the count about this, Count Bleck revealed that their minion in training, the "man in green," will allow them to pull victory over the Light Prognosticus. Here's where Dimentio's plan reveals its dark, sinister core. His plan was set up to not only get Mario on his side, but Luigi as well, since the beginning. His next plan is to unite the Heroes of Light, and get Luigi away from Count Bleck.
What he does now is, he decides that he'll "kill" the heroes and Mr. L (Luigi), in order to get him out of the count's hands, and into his own. To cover his tracks, he acts as though the minions ran off on their own accord. Essentially, he's manipulating the heroes and minions under the table, utilizing their powers to get past the Chaos Heart, which was in the possession of Count Bleck, which disabled any chance of Dimentio being able to beat him on his own--in spite of the fact that, when in base forms, Dimentio could easily kill the count. Hence, "So I had you do all the sweaty labor for me." He then decides to finalize his plans. He tells the count that Tippi uttered the name "Blumiere." Dimentio knew very well that Count Bleck had endured a sad tale of loss, and knowing that Lady Timpani--his love--still lives, would weaken him. He then powers the heroes up by taunting them--toying with them to make them angry--appearing in the mirrors and attacking from all directions. Cloning himself into the hundreds--slowly wearing down the heroes' patience for dealing with such tedious tasks. When they finally catch him, he plays a game of "magic tag," infuriating them even more. Making them stronger and stronger through anger, while the count gets weaker and weaker through sorrow.
Dimentio reveals then that he only sees the heroes as stepping stones he can use to get to his ultimate goal. Tippi realizes what he's doing, what with the attempted murder and using, and calls him a psychopath for it. Dimentio then decides to use what she believes to taunt her, and threaten her. He calls her useless many times, and laughs off her insults--making her look completely dumb.
At the end of the game, right before Dimentio's final fight, he shows that he has been assisting the heroes this whole time, and manipulates them into nearly joining him. Joining him results in him brainwashing both of the Mario Bros. and enslaving them, and having them kill Count Bleck. Refusal results in him intentionally taunting Luigi--without Luigi knowing, he is luring Luigi away from the others, that way Dimentio can get him into his own hands.
After their fight, Dimentio actually wanting to lose, but fighting all-out, he traps himself and Luigi in a Magical Box, and "ends their games." After said attack, Dimentio is unfazed, while Luigi is unconscious. This allowed Dimentio to plant a Floro Sprout in his subconsciousness. After the Count Bleck fight, Dimentio has had Mario defeat Count Bleck, who was wielding the Chaos Heart, the Pure Hearts have been drained to where the Chaos Heart is unmatched, and Luigi has a Floro Sprout in his head--everything's aligned perfectly. At this time, Dimentio appears and gets ready to kill Count Bleck and take control. However, Nastasia, seconds beforehand, had finally learned of Dimentio's treachery. Annoyed, Dimentio blasts her down--nearly killing her in the process (honestly, she should have died, but plot stopped that from happening), and calling her foolish for taking away the count's "everlasting peace" that he "so desperately wants."
This displays a bit more of his "insane" side. He never shows any remorse for those he harms--always cracking jokes even when people around him are screaming in agony, and is never seen to be afraid or dumbed, maintaining an eerily calm demeanor, even while performing flagitious acts like murder and abduction. The only instances where Dimentio is shocked at all are those right after his defeats, though he always regains his smile seconds afterwards--eventually showing that those "surprised" moments were acts to make Mario and his gang feel confident in their task. Dimentio only ever spoke to the other minions to poke fun at them, even commenting towards O'Chunks when he becomes suicidal to "humor poor me for a bit," or to trick them into doing something to advance his plans. He was standoffish towards Count Bleck in particular, and only spoke to him to get information from him. Despite his clear hatred for the count--finding him as a weakling for his broken heart, Dimentio understands the advantages of working under him, as being a minion of his allowed him to let everyone else do the work of gathering the Heroes of Light and the Chaos Heart for him, so he could later initiate his plot to destroy all worlds and recreate a multiverse in which he ruled. Unlike Count Bleck's version of the prophecy, where everything remains in ruin.
Dimentio then activates Luigi's Floro Sprout--it burgeoning beautifully, and fuses his new slave's essence with the Chaos Heart's, before imprisoning Count Bleck, Tippi and Nastasia in Dimension D, promising he'll "squeeze the life out of them later."
Dimentio had Mario defeat Count Bleck so he could attain the Chaos Heart. He can't use the Chaos Heart to its fullest, but the "man in green," Luigi, can. So, he mind controlled him, that way he can use the Chaos Heart to its fullest. Dimentio then reveals that, because he has everything he needs, everyone else besides Luigi's value to him has run its course. So, he's going to kill them, and erase them from existence. Because Mario had used the Pure Hearts already, there is nothing that can stop Super Dimentio. Dimentio then fuses his own power into the being, becoming a fully-realized Super Dimentio.
With all this said and shown, plus the foreshadowing at the beginning of the story, we can see that Blumiere was the falsified "Dark One," while Dimentio is the true “Dark One” mentioned in the Dark Prognosticus; prophecized to bring destruction to all existence.
The Void then begins exponentiating its growth, consuming many worlds in the process as its inhabitants scream in hopelessness and fear. Super Dimentio then begins playing around with the powerless heroes, slowly wearing them down, before he goes in for the kill. At that same time, Mimi and O'Chunks go beside Count Bleck, Tippi and Nastasia (the latter still unconscious), and share feelings of hope and love. Loyalty, and friendship. In response to this, the Pure Hearts burst back to life, exploding with power. Tippi takes them to Mario, Peach and Bowser right as the three are about to be killed, and empowers them, bringing them up to Super Dimentio's level of power. The heroes and Super Dimentio do battle furiously, fighting with every ounce of will power within them for their own ideal world. Worlds begin decaying, but eventually, Super Dimentio is struck fatally, and beheaded. Dying, Super Dimentio reassures the heroes--who are now bragging about their victory--that this isn't over yet, and that Dimentio had already planned in case of this. Smiling, Dimentio lets out one of the most chilling quotes in any Mario game: "Urrrrrrk... Unngghhhh... You think this is the end? This isn't finished... You can't... stop this now... You can't escape..." Laughing, he continues. "I've been saving one last surprise... Ah ha ha ha ha ha ha ha... Ciao!"
Super Dimentio then explodes, spitting out Luigi and the Chaos Heart and leaving Dimentio to die, who continues laughing. Count Bleck accompanies the heroes, informing them that Dimentio left behind a shadow of his power to continue empowering the Chaos Heart, and continue the destruction. As Castle Bleck shakes, The Void begins consuming more worlds, leaving them devoid of life. And soon... Castle Bleck itself would meet a similar fate.
The heroes hurry into the altar--the same place where Peach and Bowser had been wed earlier and the Chaos Heart had been born--to stop things once, and for all. Count Bleck states that there is only one way to stop the Chaos Heart, and that's to use the Pure Hearts once more, but with true love. He goes on to say... "that's something I'm lucky enough to possess." Bleck and Tippi ask one another one last time... "do you still love me?" And when they say yes, they take the Pure Hearts up to the Chaos Heart.
Looking into each other's eyes... together at last... the two exchange their final vows, as the Pure Hearts, Chaos Heart (along with Dimentio's essence), Blumiere and Timpani all vanish into nothingness. The worlds reset, and the game concludes, thus averting all of Dimentio's work. The Dark Prognosticus falls into history once more, and Dimentio disappears, never to return again.
