WMG / Miitopia

The whole game is a group of children's playtime

MASSIVE SPOILER ALERT!

This would explain the HP Bananas and the MP Candies. This could just be the kids taking stuff from the kitchen and using them as props. It would also explain the rather jumpy nature of the plot: kids might get bored with their role, and decide "Hey, I want to be evil!" or "Hey, I want to be good!" In the case of becoming evil, the Dark Lord could steal their faces and put them onto a monster, basically making them evil. This happened in Karkaton. And in the case of becoming good, the Dark Lord just got defeated and became the Ex-Dark Lord. This could also explain the random people as the characters, they're just kids roleplaying as themselves. Another thing: The jobs are part normal, part random. On one side, there are jobs like Mage, Warrior, and Cleric, but on the other, there are roles like Pop Star, Chef, and Flower. Again, this would just be the kids roleplaying as whatever they wanted. The weapons also make a lot of sense when you think of it like this, as the kids are just using whatever they can find and allowing their imagination to fill in the blanks. There are normal weapons like the sword, but there are also weapons like the pink ribbon. These are just things that the kids pick up, and use like weapons.

To expand on the theory above, the game isn't just any children's playtime, it's the playtime of children in Tomodachi Life

In the 3DS version, you could import Tomodachi Life Miis to cast in Miitopia. Of course the kids would pick from their neighbours and family! Not only that, but the jobs (save for the secret ones) can all be found somewhere in Tomodachi Life. Warrior, Mage and Cleric are roles seen in the minigame Tomodachi Quest, which itself may have been a Miitopia prototype. As for the Bare-Fisted Monk that makes up the fourth role, the kids might have changed it into a cat (which are easily rentable) to make it more cute and fun. The Concert Hall inspired Pop Stars, while their parents' cooking through both the Frying Pan gift and chef outfits inspired the Chef job. The more they played, the sillier it got, which is why things like Imps, Flowers and Tanks started becoming an idea. The various clothing options also might have inspired the different upgrades and such.

Both iterations of the Dark Lord were Fighting from the Inside the entire time.

And did a hell of a lot, too.

It's funny how the Dark Lord always keeps his distance from you until the final battle, isn't it? Especially after the General <Princess> fight, which is not only after the boss fight, when your party is presumably weakened, but he explicitly says his good mood was ruined. Why doesn't he just finish you off then and there? Because the host is doing all he can to stop the Dark Lord from hurting his one hope at freedom. It would also explain why he only ever kidnaps your teammates and not you, and why he spared the Great Sage during their first encounter despite the Sage being so powerful, and potentially a huge threat.

As for the Darker Lord, I believe it's best exemplified by the HP to One attack. The Dark Curse intended it to be an instant knockout attack, but the Great Sage interfered enough to weaken it. Plus, the pattern continues of the Lord staying away from you until there's nowhere left to run.

The Prince of Neksdor is a fraud, and really just a Spoiled Brat with delusions.

He never does any form of royalty, and no one in Neksdor seem to give any regard about the presence of royalty. Neksdor doesn't even have a castle. During the rescuing the Princess mission, the King investigated and found out the Prince was just a random Neksdor citizen who had been spoiled too much by his mother, and "prince" was only an Affectionate Nickname that he took too literally. This is also why the King can easily call off the betrothal without angering Neksdor.

The Prickly Couple was once like the Lovey-Dovey Couple before their marriage.

The Lovey-Dovey Couple is implied to only be attracted for superficial reasons. And as the saying goes, "love is blind, but marriage opens the eyes." As a result, they eventually ended up at odds with each other.

The deity of conveniently-placed inns is actually real.

While it may seem like just a random throw-away line said before finding the first inn, said deity actually exists, which would explain why you can find inns in places like haunted mansions, ancient pyramids and outer space.

• It may also explain why when a Mii falls into a hole you'll find them at the nearest inn.

The Guardian Spirit is the deity of conveniently placed inns.

The Guardian Spirit is always accompanying you, and all your team members save for the first one always meet you at your inn, having been summoned by the Guardian Spirit. Given how wide Miitopia is, the Guardian Spirit being able to relocate the player in their inn would be quite challenging... unless they knew the inn because they placed it there. Also when you reach certain milestones (i.e. a number of faces saved or eating bananas and candy), the Guardian Spirit speaks up about at the inn. This suggests that they are at their strongest inside inns.