This article contains major in-game spoilers.
The Dark Curse was originally a normal Mii living amongst the people of Miitopia. After years of neglect, however, he cast away his face, leaving his soul to become filled with hate and envy. After possessing a factory worker, he appears as an arrogant troublemaker responsible for stealing the faces of various Miis across Miitopia, giving said faces to monsters.
Prior to the events of Miitopia, the Dark Curse was an ordinary man who lived in Miitopia and blended in with the rest of its people. Unfortunately, because he was so mediocre, no one paid attention to him, making the man feel lonely and left out. After looking at himself in a mirror, he concludes that it was his face that made him so average-looking and decided to be rid of it. Without a face however, he could not live, and before long he faded out of existence, leaving his soul to become filled with hate and envy. As his hatred grew, the Dark Curse became a shadow of his former self, no longer wishing to simply "fit in" and instead force others to suffer. Furthermore, his soul was completely powerless without possessing a face, with his only ability being to possess people or communicate through telepathy.
A Factory Worker
Although it is unknown how many people the Dark Curse affected, at some point it was sealed away in a forbidden box that eventually ended up in a factory that produced HP Bananas. The Dark Curse spoke to one of the factory's employees and promised them great power and wealth. Tempted by the Dark Curse's offer, the employee agreed to open the box containing the curse, leading to them promptly being possessed by the Dark Curse not long after. Now under control of a face and dark powers as a result of his hatred, the Dark Curse dubbed himself The Dark Lord, and quickly began plotting his revenge against Miitopia for their negligence of him.
Defeat and a New Body
After a long, tough battle, the Dark Lord is defeated, and the Curse escapes the now-broken medallion. The factory worker he possessed leaves the castle, confused by what happened, but still proves to not be the end of the Dark Curse. In a rage, the Dark Curse attempts to possess the hero, only to be blocked out by the Great Sage, unintentionally possessing them instead. This, however, only makes the Dark Curse even more powerful, as his original powers are now combined with the Great Sage's powers. Dubbing himself The Darker Lord, he leaves the castle, and creates a new castle with his new powers.
The Fate of the Dark Curse
Eventually, the Darker Lord is also defeated. However, even this is not enough to destroy the Dark Curse, and it appears as the hero celebrates their victory. Now angrier than ever before, he attempts to possess the Great Sage again, only for the Sage to trap him inside a confined sphere. With the Curse struggling to get free, the Great Sage tells the Hero of the Dark Curse's origins, and how he came to be known as this Dark Curse. They then ask the protagonist what can be done with this shadow of a soul, allowing the player to choose the Dark Curse's fate:
Ending A: Break the Curse
The hero, deciding that the curse should be broken, uses the divine power to obliterate the Dark Curse. As the soul is destroyed, the human that became the Dark Curse says one last thank you as he fades away. With the Dark Curse gone once and for all, all of the faces he had stolen return to their rightful owners, while the monsters he created disappear. Peace is returned to Miitopia.
Ending B: Save Him
The hero decides that the person that became the Dark Curse should be revived as his human self, to which the Great Sage, though shocked, agrees to. Using the divine power, the hero resurrects the Dark Curse's human form, restoring his face in the process. The Dark Curse, realizing that he is back to normal, thanks the hero for "saving them". The Great Sage then takes in the reborn Dark Curse as their apprentice, in order to atone for all the evil they committed as the Dark Curse. With the Dark Curse human once again, all of the faces he had stolen return to their rightful owners, while the monsters he created disappear. Peace is returned to Miitopia.
A Second Encounter
If the player chooses the second ending, the reborn Dark Curse will be seen in New Lumos, although oddly separated from the Great Sage, at the edge of the city after the player completes the city's first three districts. As the Reborn is approached, he will ask the player if they know who he is. Regardless of their answer, the Reborn will explain that they have one final task, and will summon the Tower of Dread. He is not seen again for the rest of the game.
- The Reborn Mii is the only NPC Mii who cannot be recast from the Journal, although he can still be recast by fighting the Darkest Lord again.
- This results in it being impossible for one to generate a QR code if a new Mii is made from scratch for him.
- However, in the Nintendo Switch version, the Dark Curse is able to be edited, copied, or given makeup and wigs in the Mii Characters section.
- When choosing to create a new Mii for this role, the game will not allow the player to name the Mii. His name will automatically be set to "???" unless a premade Mii is chosen.
- This is not much of a problem because his name is not used anywhere in the game besides the credits or when he rarely appears in the Quizmaster's quizzes.
- In the Nintendo Switch version, this is different, as it uses the Nintendo Switch's Mii maker which already has a naming function built in.
- The spirit's last "thank you" is a red herring as its death prevents the Tower of Dread from appearing.
- However, the answer is not locked. The player can fight the Darker Lord again and choose to save him, then the Tower of Dread will be accessible.
- If "Break the Curse" is chosen, then he will not appear in the credits, with that portion only showing the Great Sage.
- After defeating the Dark Lord, the Dark Curse's symbol will appear for the remainder of the game (even during the postgame) whenever a monster is encountered.
- In the Quizmaster's "Who Am I?" quiz, he will be called the Dark Curse, and not the Reborn.
- If the player deletes the Reborn, he will be replaced with the default male Mii (named "Mii) in cutscene viewings. This makes sense, as the Dark Curse is supposed to average-looking, and the nose and mouth line up with what the Mii's face looks like in the backstory cutscene.