Everfree

"YOU IDIOT!" Celestia roared and leaped to an aggressive stance facing him, and as she did, a great maelstrom of heat and light erupted around her, incinerating all plant matter and melting the earth and stone beneath her within a sphere just outside the diameter of her wingspan in an instant. "DO YOU THINK WE GAVE YOU THE POWER OF AN ALICORN WITH THE THOUGHT OF YOU ASKING PERMISSION EVERY TIME YOU SOUGHT TO DO SOMETHING IN MIND?"

Celestia's Royal Canterlot Voice, used now as very scarcely before, was so powerful that it directed the blazing heat at Event Horizon in a powerful breath of fire that most dragons could only dream of. The human-turned-alicorn-prince spread his brown and black wings as though to brace himself against the torrential blaze and covered his face with one foreleg. The tears brought by the sheer force of her voice were immediately evaporated off his face and he was almost certain his eyes were going to burst right out of his skull.

"Ow! Ow ow ow! Ow, stop that! Jeez," he muttered as he waited out her tantrum, trying to keep her from burning down the forest behind him in the process. (This is just like walking behind those jets in Kuwait all over again. ...wait. It should be *much* hotter than that right here. Why am I even still alive? ...oh. Right.)

He was maintaining his calm until he had by chance managed to hear her mutter under her breath, once she stopped shouting, something to the effect of giving him that power so he wouldn't cower before her will. Then it was his turn to lose his temper. Horizon flapped his wings once, with nearly enough force to lift him off the ground without the assistance of magic. Celestia's flames swept back over her and dissipated. Of course, since they were hers, they weren't going to hurt her. However, the point was made clear and she stopped, waiting once again for him to explain himself. The semi-lava beneath her cooled enough to resume a mostly-solid state, but she remained hovering.

"YOU SAID YOU GAVE ME THIS POWER BECAUSE YOU FELT YOU COULD TRUST ME WITH IT! DOES THAT WORD MEAN NOTHING TO YOU?" he bellowed back, his voice forceful enough to push her to the far side of the hole she melted into the ground. There was a slight pause before he continued, in a tone somewhere between his mumble and a normal speaking voice. "Huh. Shouting can be fun sometimes. Anyway, I'm fully aware that I don't need to ask permission for, or even inform you of my doings. Even those as relevant to a given part of Equestria as this one. I just wanted to give staying on good terms with you a shot, especially considering all the things that are going to happen to you over the next year or so. I know we've had our differences, but I don't want those to be all we've had. Also, you're going to want to enjoy that authority while you still have it. You're going to have a tough time getting it back once it's gone."

(This stallion incites all kinds of extremes in me,) Celestia thought as she finished the transition from a blazing temperamental outburst to shocked silence, now certain that her heart was pumping ice water through her body. "Y-you mean... you're finally doing  it? You're declaring war against Equestria? Even though that one kingdom, its army, and a handful of ponies is all you have to your name?"

"What? Oh no! Don't be silly, Princess!" Horizon chuckled "That war is already over. You lost, by the way. In large part because you never noticed it starting."

"What..." Celestia knew she was missing something. Sure, Castle Everfree was now populated by ponies who resented or felt abandoned by her or her favorites, but that wasn't enough to consider a war having been won, even if he now had most of her army, and they were better utilized in service to him. The crux of the problem is that she didn't remember a single clash greater than the spat they just had, which was typical of interactions between the two. "But we never even..."

"Fought? Well of course not, you mad mare! You asked for a bloodless coup, and I gave you just such a thing. Well, I am giving you one, anyway. You can still stop it, if you try, now that you know it's happening!"

"You're bluffing!"

"I am not!" he retorted, in a manner she thought was unusually petulant, until she remembered that he took pride in his honesty.

"You must be! You can't exp-" Celestia was interrupted by the impact of a dawning realization: the full scope of just what this stallion had been doing with his time.

The bulk of her Royal Guard, re-purposed as his Equestrian National Guard, were distributed more or less evenly among all the major towns and cities of Equestria, on rotating shifts of training, spending time with their families, and performing random acts of heroism and kindness. That's why she didn't see them at his castle. The new Singularity Bolts were likely doing something similar. And like the Guard, they were probably wearing those new uniforms with his nation's insignia on them. His military was making a massive yet non-hostile show of force. If her Loyalists tried to drive them out, she would appear the aggressor, despite their presence technically being an invasion.

Also in various, highly visible places throughout those towns and cities were massive posters he commissioned of local artists, depicting such adorable things as:

Pinkie Pie offering a bright yellow balloon with the word 'HAPPINESS' emblazoned on it in dark blue letters with the subtext 'For Best Results: SHARE!'

Shining Armor and Cadance sharing a warm hug with the subtext 'LOVE: As Always, Held By TRUST!'

A meeting of Twilight Sparkle's new Friendship Council with the subtext 'FRIENDSHIP: Maintained Through Good Communication!'

And many others about such whimsical things as 'The Classics', 'Family', 'Dreams', and so on and so forth, all together including just about every happy facet of the pony world, except for her domain. In just that moment, Celestia had the faintest inkling of how Luna must have felt when they first took their thrones. When her complaints of growing loneliness were justified by Celestia continuing to ignore them.

Then there were the Changelings to consider. Horizon saved them at the brink of the extinction they were facing as a result of their  loss to Canterlot, mostly by accident, just as he was mostly unintentionally finishing their eradication prior to that point as he wrestled with his unwanted power to drain (usually Dark) magic. Now there was a new brood of them, stronger than the one that attacked her capital, and it took no stretch of the imagination to guess where they came from. But they weren't attacking now. Chrysalis had been taught that love is not a commodity, and had been given citizenship in his kingdom, pending joint citizenship in Equestria. If the Changelings were accepted into pony society and especially if they managed to properly integrate, Horizon would  have even more forces in her towns and cities, and she would be powerless to drive them out.

There were other things too, now that she thought about it. Little things that did not bear mentioning individually, but which collectively, especially alongside those first three, all pointed in the direction of her own kingdom seeing gradually less favor in her. The enormity of what she'd asked of him, what he was giving her, had finally struck with full force. She had to sit down because her hind legs suddenly weakened, and was grateful for the stone beneath her having returned to a solid state.

"How...?" she asked, her question doubling as a desperate gasp for air.

"Propaganda is a powerful thing. You wanted me to play the part of villain and I did. In fact, I went so far as to play the worst kind from my own world, minus the genocide, a factor I don't plan on including." he replied as the sky over Everfree darkened with the threat of one of those terrifying natural storms. "I played the part of the villain who convinces the world he is good. And more importantly, some time in the foreseeable future, I will convince it that it doesn't need you."

"But... why?" Celestia asked, on the verge of tears and already fearing the answer. "Why would you do such a thing to me?"

"Because... IT'S WHAT YOU WANTED FROM ME! YOU DEMANDED THAT I DO THIS TO YOU! TO PROVE TO YOU AND ALL EQUESTRIA THE UNMITIGATED EVIL OF MY KIND!" he shouted, losing his temper and then regaining it a few heartbeats later. Rage simmered down into bitterness. "I hope you're happy. I went to a lot of trouble to bring about this destruction you sought at my hoov- hands -they were hands at the time- ever since we first met."

"What? What makes you th-"

"DON'T TOY WITH ME, CELESTIA!" he glared directly into her eyes, and she wilted away, reminding them both why he always took such care to avoid meeting another individual's gaze, especially here in a land of friendly cowards. Princess Celestia was something of a warrior, but he had caught onto her secret shame and now she was aware of that. "I saw it in your eyes, when it was first pointed out that many of my kind ate the flesh of other creatures. There it is again! I wonder if you're even aware of it."

"Aware of what?" Celestia asked, hoping that he believed something else of her than the truth. Not much could be worse than that. But he already told her what he knew, and regardless of what she tried to deny, he was right. She tried anyway, right up until her gaze met his again and once again she felt him looking right through her facade.

"You're going to make me say it... Fine, I'll say it!" he closed his eyes, freeing her from their terror as he took a deep breath. It was a really deep breath, and more importantly, it felt as though the entire universe was calming down with him. She wondered if this might be the real power of the Star Pony race the Princesses had created by transforming a human into a magical pony. The only one of his kind, ever, if anyone sane was to have their way about it. He snapped her out of her reverie by finishing his thought. "You're a masochist."

"I beg your pardon?" Celestia blinked, unmitigated confusion once again superseding all other thoughts and emotions. "A masowhatnow?"

"A masochist. You believe that you deserve to suffer. That the path leading you to this moment merits some kind of punishment being in store for you. I don't know why, but you've latched onto the idea of me being the one to arbitrate that punishment, and you gave me no other choice, so I did."

"I don't think-"

"Celestia! Please stop trying to lie to me! Least of all when the truth is so obvious some other ponies might start to pick up on it if you continue this way."

"Wait... you really believe nopony knows, or even suspects?"

"I imagine most ponies have naturally avoided trying to get too intimate with you, and those that are have their own problems right now. In any case, I don't believe you deserve any punishment for those of your actions up to this point that I know of. Except for that plan to give all the alicorn magic to Twilight. That was plain stupid. She's a natural ball of stress as it is."

"Yes well, hindsight is- wait, what problems?"

"What?"

"You said the ponies that are intimate with me, by which I can only assume you mean my closer acquaintances, have problems at the moment. What problems?"

"Oh that. Well, there's a list, so unless you want to risk missing something important, you might not want to bolt off at the sound of  the first one that excites you."

"Ohh..." Celestia cringed, already regretting having confused the term 'bloodless' for 'harmless'. "Ok, go."

"Ok then." Horizon summoned a clipboard with a list on it and started ticking things off as he read. With each item, Celestia found it even more difficult to stay and listen to the next.

"Thanks to your sister giving me her Nightmare ego, she can no longer access a pony's nightmares and alleviate them. She's not handling that well. Incidentally, I gave that to Trixie, because Nightmare Lulamoon is exactly as intimidating as it sounds, and for that reason I knew it would piss off the Nightmare ego. It did, and it's pretty funny.

Ahem. Anyway...

Thanks to my having converted the Changelings from a net loss of Love in the world to a net gain of it, Princess Cadance currently has more power than she can handle. Due to her special talent not being magic as Princess Twilight's is, she is taking considerably longer to adjust.

Due to my having made off with Spitefire and most of the Wonderbolts, Rainbow Dash's dream of joining them is now up in smoke. She is taking that about as well as can be expected. Lightning Dust is rubbing that in her face. Letting her do it is, unfortunately, the price of Lightning's loyalty.

Due to Sweetie Belle's newfound success as an idol and that cutie Coco Pommel's rise to the fashion scene causing tumultuous fluctuations in Rarity's business, the mare has been showing warning signs of being on the verge of a psychological meltdown. And not a cute tantrum like you had just a little bit ago, I mean something serious there may be no coming back from. I tried helping her, but depending on which of my forms I've taken, she pays either no or way too much attention to me and not what I'm trying to say, and either way I can't get through to her.

And lastly, as part of my grand plan to usurp your throne, I gave it to Princess Twilight."

"WHAT!?"

"I told her you were taking a little one-year vacation away from the tedium of your job to remind yourself of who you are, and wanted her to handle administration while I managed the Sun, and also the Moon because Luna has not been feeling well lately. She was positively thrilled, by the way. The day of, though, she'll probably reduce herself to foaming at the mouth and stress-induced convulsions."

"You... you lied. I thought you hated lying. That I'd be able to see right through you when you did."

"Well, when I lie, you'll probably know. In any case, you might want to get some rest tonight, whenever you manage to bring the sun down, and decide which of your nearest and dearest you're going to have remind you who you are first."

"But I- But you... oh." Celestia said, as she struggled to take flight, her mind whirling and her heart equally out of control. (He did all this... allof this, for me... the conniving bastard.)

"I hope next time you won't forget the value of your life, Princess!" he shouted up after her. "It's a wonderful life, after all!"