“Once upon a time, in the magical land of Equestria, there were two regal sisters who ruled together and created harmony for all the land. To do this, the eldest sister used her unicorn powers to raise the sun at dawn. The younger brought out the moon to begin the night. Thus, the two sisters maintained balance for their kingdom and their subjects: all the different types of ponies.

“But as time went on, the elder sister grew greedy. Though the ponies relished and played in the day and honored her above her younger sister, she wanted to become queen of both night and day. One fateful day, she turned upon her younger sister. The younger sister tried to reason with her, but the avarice in the elder one’s heart had transformed her into a wicked mare of fire and hate: Corona. She vowed that she would reign forever over day, night, and everything in between.

“Reluctantly, the younger sister harnessed the most powerful magic known to ponydom: the Elements of Harmony! Using the magic of the Elements of Harmony, she defeated her elder sister and banished her permanently into the heart of the sun. The younger sister took on responsibility for both sun and moon, and harmony has been maintained in Equestria for generations since.”

Oh, look, I can re-write the opening monologue. I bet that makes me a fantastic writer! No, not really. Still, it was something that needed to be done, so there it is.

The thing is, there's a fundamental difference in a world where Celestia goes evil and a world where Luna goes evil. The night is something that is seen as just, in and of itself, creepy, mysterious, and maybe a little evil - and so it follows that princess, the alicorn, the goddess of the night, Luna, must herself be creepy, mysterious, and maybe a little evil. Thus it probably wasn't a big surprise when Luna turned to evil in the main My Little Pony universe. Certainly it was easy to accept.

But if Celestia turns evil, that's a different animal altogether. Celestia is the day, the sunlight. She is what allows ponies to grow food, to stay warm, even so basic a thing as see: all thanks to the sun. So a world where the goddess of the Sun turned to greed and evil, but was then defeated by the creepy and mysterious sister who since then has been keeping the day-night thing going on schedule, is going to be a different Equestria from the one we've known on a very, very fundamental level.

This blog post is just a sort of stream-of-consciousness write-up of some of my thoughts on the subject. Feel free to add anything you like in the comments section!

Betrayal
This, I think, is going to be the most fundamental feeling that the ponies feel towards Corona. Princess Luna turning into Nightmare Moon? Eh, knew it was going to happen. Could see that coming from a mile away. But Princess Celestia becoming Corona? Celestia had everything she could ever want. She was more loved, more respected, the elder sister, the bringer of the beloved dawn. So when she turned to evil and tried to become goddess-queen of Equstria, is cut deep into the racial psyche of the pony tribes. If even the Princess of the Sun can turn to wickedness, then anything can. Ponies might not be more pessimistic, but they're certainly more open to the idea of someone lying to them or trying to scam them. It would take more than a song and dance routine, basically, for Flim and Flam to pull what they did in this universe.

Corona is not Forgotten
Now here, we enter into a fundamental difference between Luna and Celestia. I don't think Luna would stand to have her sister's fall into fire and hate be morphed into a holiday where you hand out candy to children. Aside from it being very difficult to imagine a daylight-themed Halloween, it just doesn't seem in-character for her. Now, mind, there *will* be a day set aside for the memory of Celestia, probably the summer solstice, but it's a day of mourning, not a day of tricks and treats. Similarly, Luna would not allow Celestia to simply fade into memory - and even if she was of a mind to let that happen, the deep, race-wide sense of betrayal that the ponies feel towards Corona wouldn't let that happen, either. Everypony knows the story of Corona, everypony would recognize her on sight if she were to return.

The Sun is Bad
Corona isn't just the corrupted goddess of the sun. She *is* the sun, sealed away inside of it. What does that mean? Well, most ponies don't really know. Does it mean that, in some ways, she *is* the sun? Does this mean that the very light that is warming you and letting you grow your crops and see what's in front of your own face, is in fact being provided by Corona? That is a less-than-fun thought. Like the human equivalent of learning that all dreams stem from Great Cthulhu. Of course, the ponies can't just dodge sunlight, or become nocturnal creatures: everything they need to live needs to be tended to in the daylight. Still, I think this will translate into a few superstitions and habits. Hats are going to be more common, in order to shield your eyes from the sun. And I imagine that a tradition of noontime siesta has formed, or something like that. At noon, when the sun is highest in the sky, ponies generally head indoors. They don't necessarily nap, as the term "siesta" suggests, but they basically spend an hour or so waiting for the sun to leave its high position.

Princess Luna is in Charge
So Celestia goes evil, is thrown down, and then sealed in the sun. Princess Luna is now in charge. Princess Luna. The creepy, mysterious, and maybe a little evil goddess of the night. How do you feel about that, Equestrians? Probably not so good. Probably a significant number of Equstrians believed that Luna may have had a hoof in the creation of Corona. Luna denies it, of course, but do you really believe her? She's the goddess of the night, ergo, darkness, ergo, evil. Of course, she is a goddess, so there's not much you can do about it. As the years go by and Luna doesn't really undertake any action to bring about eternal night or something, so gradually you settle into a kind of complacency. Luna is creepy and mysterious...but maybe you were wrong about the evil part. But never forget: she is the goddess of the night, not the day. The goddess of everything you fear, not the comforting warmth and light of the sun. She may seem benevolent, she may genuinely be benevolent, but ponies are always going to have this sense of distance from her.

Luna's Reign
Luna is not her sister. She is a blunt, hoofs-on kind of pony. She is also somewhat feared by the populace for being a deity of the night despite not being a bad pony, but over a thousand years she's come to accept this - and being in charge for a thousand years has allowed Luna to build up a large stable (no pun intended) of friends and associates, not to mention that despite the general mistrust, there *is* a sizeable portion of the pony population that is grateful to Luna for saving their behinds from Corona. Luna also has direct representatives of her Court in every major city and town in Equestira, including Ponyville. These representatives form a part of the local government and report directly to her. Theoretically they wield a tremendous amount of influence; in practice, Luna looks poorly on ponies who attempt to misuse their power. Mostly they serve as glorified messengers between their appointments and the Court, and relay her royal edicts directly to the populace.

Anyway, that's about all I can think up at the moment for this blog post. Like I said, I welcome any questions, comments, concerns, or criticisms.

Thanks for reading!