The ponies of Equestria know Harmony as not just an ideal, but as a force that actively shapes their existence. It guides them through their lives, brings them prosperity and ensures good will triumph over evil most of the time.

However, exposure to it can be unpredictable for those crossing over from other realms. Sufficiently long stays in Equestria can even lead to a change of form to one indigenous to the land.

And those unlucky enough to be slated to become a source of Harmony itself may find themselves unable to leave.

Translation: This fic contains the gradual transformation of a human (male) to a very young alicorn filly.

Set just before Season Five. Non-Earth human and an Equestria that's slightly different.

Cover Art by the talented Mix-up check out his work here: http://amalgamzaku.deviantart.com/

Sora was an average teenage boy, though average was an understatement. At the age of fourteen, he was thrust into a battle between light and darkness, wielding a mystical weapon known as the Keyblade, saving worlds from creatures known as the Heartless and finding his friends, Riku and Kairi. He has saved the universe many times from the Heartless, saved Kingdom Hearts from being controlled by those with evil intentions, and has made new friends in each world he visited.

However, he fails his mark of mastery exam after almost getting himself killed by Xehanort's younger self, needing to be rescued by his friends as Riku and Kairi become Keyblade Masters. Needing more training before he can retake his exam, Master Yen Sid gives him coordinates to somewhere in the galaxy, though the information on what was there or why was unanswered, obeying his teacher. But as he was close to reaching the coordinates, his own gummi ship, which he crafted on his own while on a break a week prior to his exam's failure, malfunctions for some unknown reason and crashes into the world of Equestria.

With no way to make it back home, and Equestria too far from the rest of the worlds to contact his friends or fix his ship, Sora is stranded on this new world until someone realized he's been missing. Until then, he's going to have to fit in, his magic transforming his body into being a part of the world like in many others he visited in the past, and be patient. Little does he know that there were also dangers that lurked in this world, aside from any Heartless that may appear.

Sora's story takes place after the events of Dream Drop Distance, his adventures beginning in Equestria before the season 1 premiere of My Little Pony: Friendship is Magic.

Kingdom Hearts is owned by Square Enix and Disney. My Little Pony: Friendship is Magic is owned by Hasbro.

EDIT: Those who are new to this story, there are links in a majority of the chapters where they lead to soundtracks of Kingdom Hearts to help build an atmosphere in the story. Sadly, most of them may come up as dead links because those videos had been taken down by the YouTuber for some reason, even if there are some still active by that same person, or they'll be gone as well if they happen again. With how many chapters I've put in this story, and how many links there might be, I don't have the patience to take them down or find new links with the right music I chose for those moments if I can remember which ones. So, up until Equestria Girls: Legend of Everfree (Part 3), ignore the links, as much as I hate to say that with the hard work I've done. Hopefully this crossover will be as enjoyable without music as it keeps on going.

Formal Premise: The inventors of the Mirror wanted to create a device that could channel infinite magic and grant wishes. The hard part was making sure those wishes would never destroy the world. Showing a person their heart's desire is a sensible precaution to put into a wish-granting machine designed NOT to go horribly wrong.

The Atlanteans got close, even managing to imbue some amount of intelligence and morality into the Mirror. But they never finished their work; the Mirror never DID get to the point where it could grant wishes... at least, nobody believes it ever got to that point. But then, nobody has ever been trapped inside the Mirror and returned to tell the tale.

When the Mirror traps someone inside itself and outside of Time, that person and their consequences can no longer affect the world. In that circumstance, with a person fully under its power, the Mirror isn't limited in what it can do. Sometimes, it can even grant seemingly incompatible wishes.

But complex problems require complex solutions. In this case, the Mirror takes a few massive liberties about how, exactly, it satisfies the wishes of both Harry Potter and Lord Voldemort. Namely, it sends them to a world of ponies.

Informal Premise: This is a crossover between MLP and Harry Potter and the Methods of Rationality, not just Harry Potter. No matter how accessible I try to make it to those who haven't read HPMoR, those who HAVE read it will undeniably have an easier experience reading this story.

HPMoR is the second most popular fanfiction of Harry Potter, at least according to fanfiction stats. It involves Harry studying & dissecting the wizarding world with science. Not with technology, with actual science. That is, he uses the experimental method, generates and tests hypotheses, and in the words of his Occlumency instructor, "wants to discover the underlying rules of magic to become all-poweful".

THIS fanfic brings THAT version of Harry Potter to Equestria. It also brings that story's version of Voldemort.

If you want the best reading experience, please go read HPMoR first. It can be found on fanfiction dot net, or on its own website, or even on any podcast app, as it has its own fan-made audiobook with 30+ contributing voice actors, production quality, sound effects, music, etc. (which is more than can be said for most PROFESSIONAL audiobooks).

Link to HPMoR on fanfiction: https://www.fanfiction.net/s/5782108/1/Harry-Potter-and-the-Methods-of-Rationality
Link to HPMoR on its own website: http://www.hpmor.com/chapter/1
Link to audiobook (though the website isn't nearly as good as podcast apps): https://hpmorpodcast.com/?page_id=56

All forms of HPMoR that I've encountered are high quality, but that doesn't mean it's for everyone. You can probably read the first few chapters of HPMoR in thirty minutes or so. If it doesn't appeal to you, this story probably won't appeal to you either.

For those who haven't read Methods and want to read this story anyway, the first two chapters are going to be the most confusing. They're mostly housekeeping and stage-setting, barely touching the MLP universe beyond the new setting.

And I think the same advice Yudkowsky gave for HPMoR applies here. The story starts hitting its strides around Chapter 5, if not sooner. If you don't like it by Chapter 10, best just to give up and read something else.