Canterlot Castle, its coziest room.

“Princess, we need to talk!” Twilight said, eyes narrow, slight pout on her lips.

Celestia blinked. Then she slowly sat down her tea cup.

“What is the matter, my student?”

“YOU!”

They stared at each other in silence.
After a few long seconds Celestia sighed.

“I’m sorry, Twilight. I will, of course, replace your birthday cake. As you know, I can’t help myself when it comes to…”

“NOT THAT!” groaned Twilight so loud that her words slightly reverberated within the room they were currently sitting in.

“Oh?” Celestia raised an eyebrow.
Twilight has to be VERY upset, she thought.
Usually she is too afraid of me to be this bold. Not that I want her to be afraid, of course!

“How else have I wronged you?” she asked carefully, her tone filled with the guilt a mother feels when she fails to buy the right toy for her foal.

Despite her smoldering anger, it took Twilight some courage and willpower to spill the beans.
She squinted her eyes, her cheeks puffed and her wings flared.
Then, with a sudden vocal burst…

“I’M NOT YOUR CLEANING LADY!!!”

Silence.
Huffing student.
Staring mentor.

Twilight took in some air. “Sorry, Princess. I needed to get that off my chest… for years!”
She adjusted herself in her seat. “Let me elaborate!”
She cleared her throat.

“Since you’ve sent me to Ponyville, Princess, you’ve let me and my friends handle every major threat to Equestria. And while I’m very thankful for the trust you put in us… it’s getting quite annoying.”

Celestia gulped ever so slightly. She knew this day would come. The day Twilight would call her out…

For the first time in their relationship, Twilight spoke to Celestia like a scolding teacher.

“Every time! Every single time, we have to clean up the mess! And by 'mess' I mean all the villains, catastrophes and the trouble they cause! Even though you don’t do… well... nothing, you certainly do very little! With all due respect, some of your critics call you ‘Uselesstia’! I’m not one of them, for the record.” - she added quickly.

Sweat was forming on Celestia’s forehead.
“But Twilight... after all these years… you should know how weak I am… um… d-don’t you remember my fight with Queen Chrysalis… uh… I was SO helpless… and um… all those other times… I got captured… oh woe is me! Even a… a Breezy could defeat me! Yes, right! A Breezy!”

Celestia chuckled. Too loud and too expressive.
“I’m the perfect example of a damsel in distress, tee hee…”
She grinned way too wide and far too awkward.

Twilight was silently looking at her with half lidded eyes. Celestia’s pupils wandered nervously from left to right.

Then, Twilight let out a long sigh.

“You really are not an actress.”

The young alicorn suddenly hauled a very old, treasure-chest-sized book onto the table.

“This is a record of all attacks on Equestria during your sole one-thousand-year rule.”

She opened the leathery cover to some random parchment page and read:
“Let’s see… year 147 of your rule, 20^th of July… A horde of crimson Dragons was seen crossing the Equestrian border, roaring ‘Death to thee, Ponykind!’…
21^st of July… no sign of said horde.”

Uh oh!, Celestia thought to herself.

Using her magic, Twilight flapped through all of the following pages.
“The crimson Dragons are never again mentioned in this record.”

She picked another random page.
“Year 562 of your rule, 2^nd of October… The Great Old One Cthulhu is witnessed rising from the sea…”
Again, she magically flapped through all the following pages.
“Same here! Not a single mention afterwards!”

Celestia shifted in her seat, uneasiness all over her sweat covered face.
“Oh… um… I remember these incidents. The dragons and the Great Old One… just left! Yes, they left! Into space! Tee hee… The ponies keeping the record must have simply forgotten to write it down.”

Twilight didn’t know if she should smirk or frown.
“Is that so? Well, I have read through the whole record…”
(a fact that didn’t surprise Celestia in the slightest)
“…and there are literally thousands of examples like these! In fact, there is not even one calamity mentioned here that did NOT mysteriously vanish!”

Celestia grinned sheepishly.
“Space is… really vast!”

Twilight shut the oversized book with an angry jolt of her hooves.
“Please, Princess! Stop denying the truth!”

The little purple inquisitor put a hoof on the book.
“Even if we completely ignore this record, there are way too many contradictions! Equestria is surrounded by countless threats: Dragons, Griffons, Yaks, Storm Monkeys, Bronies, Minotaurs, Elder Things… the list goes on and on! Not to mention all the scary monsters and creatures WITHIN Equestria itself! Yet somehow… miraculously, I might say… not even a single village has been destroyed. Not a single pony got eaten by a terrible monstrosity. And no enemy army ever managed to conquer even a small part of the land. Countless unimaginable dangers around, but Equestria still stands, even after a thousand years. Seriously Princess, there is only one explanation how this could be the case under your rule and you know exactly what I’m talking about! It’s YOU!”

Twilight flung her forelegs in the air.
“You move the Sun EVERY day, for CELESTIA’S… pardon… YOUR SAKE! One has to be a fool to think you are weak!”

The young mare took a deep breath.
“Princess! Drop the act! …You aren’t good at it anyway.”

Celestia frowned and her ears dropped. She rubbed her foreleg and looked away.
“I’m sorry for lying to you. I will be honest from now on.”

Twilight became less tense. Her eyes went from narrowed to slightly sad.
“I’m… sorry, Princess… I’m just so frustrated. But why? Why didn’t you ever help us directly? You could have defeated every villain that’s ever threatened Equestria, yet you threw all the fights.”

Celestia looked into Twilight’s eyes.
“Because I wanted you to learn how to handle crises, how to be a leader and to push yourself beyond your limits. How are you going to grow as a pony, if I solve every major problem? And not just you. Your friends grew from these experiences, too.”

Twilight sighed.
“I know that already. But that’s not the whole truth, is it?”

Celestia closed her eyes and inhaled deeply.
“No… No, it isn’t.”

Twilight leaned closer, curiosity sparking in her eyes.
“Soooo… what is it then?”

Celestia looked around carefully. Then she leaned closer to Twilight.
Holding up a hoof beside her muzzle, she whispered:
“Constipation.”

Twilight pupils shrank to the size of pinpricks.
“WHAT?!”
She got angry again.
“Is this one of your jokes?!”

Celestia raised her hooves, signaling Twilight to calm down.
“Please hear me out!”

She cleared her throat.
“It has to do with the feeling of guilt. Whenever I defeat a foe by hurting them, it lays very heavily on my conscience. It keeps me from sleeping, it reduces my appetite and it causes me… well… constipation.”

Twilight stared at her in silence.

Celestia continued.
“Aside from being without Luna, this was my greatest ordeal during the last one thousand years. You must know, Twilight, I despise violence! I loathe it! Even if it’s justified in order to protect my ponies. I tried to use as little strength as possible in each fight, but still, it was always way too much…
Every time I severely hurt an enemy, it causes me about two weeks of constipation. And if I accidentally kill one, it lasts about a year!”

Twilight hasn’t been blinking for a minute now.

Celestia seemed to feel a bit embarrassed.
“I’ve spent so much time on the toilet, that some ponies started to mistake it for the throne. These ‘sittings’ were by far my most challenging fights.”
The painful memories caused Celestia to rub her buttocks with a hoof.

“So, when you and the other Element Bearers came into the picture, I selfishly took the opportunity to end my millennium of suffering by burdening you and your friends with the responsibility of defending the country. I’m very sorry for that, Twilight.”

After a few moments, Twilights confusion softened.
“I-I-It’s okay, Princess… You didn’t do it only because of that. But… why are there no records about your fights? Why are the threats mentioned, but not their defeats?”

Celestia sighed.
“That’s… another selfish decision of mine. I didn’t want ponies to see me as a monster, even though I am one. Whenever there were witnesses to my battles, I erased their memories with a spell. At least of the ones who were able to write.”

Twilight, with concern in her eyes, leaned over and put a hoof on Celestia’s foreleg.
“You are not a monster! If anything, you are a hero! You’ve been singlehoovedly defending Equestria for one thousand years, despite the pain it caused you!”

Celestia still looked sad, but smiled a little nonetheless.
“Thank you, Twilight. And I am also very grateful, that you will continue to take care of all the threats to Equestria.”

Twilight jerked back.
“What?! Nuh nuh nuh nuh nuh nuh no!” She shook her head in an almost playful manner.
“The whole POINT of this conversation is to get YOU to do your job again!”

Celestia’s pupils went small.
“B-B-But… But what about my bowels?! There is no spell in the world that helps with that!”

Twilight blew a raspberry.
“Pffft, have you ever met me?! I have thought up the perfect plan in the last five seconds, of course!”

Twilight hopped up from her seat and grabbed Celestia’s hoof with hers. She walked out of the room, while dragging Celestia behind, like a foal dragging its mother into a toy store.

“All you have to do is to learn some proper fighting techniques, so you have better control over your strength. Then you won’t severely hurt your enemies anymore! How hard can it be?”

Vastly underestimating the energy-output of the very Sun, the smiling young alicorn pulled her mentor towards the castle’s training room.

Celestia gulped and wearily glanced towards the next bathroom door.

Year 562 of Celestia’s sole rule.
2^nd of October.

Celestia was tired and rubbing her temples.
It was always the same:
They come.
She tries talking to them.
Everything goes to Tartarus…

“BLUEARRGHHH AAAAAARRRRGHHH URRR BRAUGHGHAAAAAA!!!!!” Cthulhu, the Great Old One, argued, index finger held high.

“I see your point, Great Old One, but that hardly justifies the destruction of the world.” Celestia, a few centuries younger, responded to him.

“BRUUUUUAAAHHHH AAAAAAAAHHHRGHHHHH!!!” he eloquently expounded.

Celestia cocked an eyebrow.
“Excuse me, but I just don’t get how genocide counts as charity!”

Cthulhu has had enough of the stubborn little pony that was about a thousandth of his size.
He had been patient.
He had been reasonable.
But some creatures, he admitted to himself with an inner sigh, are just beyond common sense.

“OOOORRGGGHHHH THMRRRRR KUUUUURRRRRUUUUUHHH!!!”
(“Only death can cure fools!”)

His giant hand violently shot towards the alicorn.

Startled by the sudden attack, Celestia yelped.
“EEEEP!”
Shutting her eyes tightly and turning her head away, she lifted her right hoof and flung it towards the impending giant hand, only milliseconds away from her.

One should know, the Sun contains about 99.86 percent of the Solar System’s mass and produces an unfathomable amount of energy every second (for all readers across the Magic Mirror: About a million times more than all of human civilization consumes per year, i.e. a one-trillion-megaton bomb).

And one must also know, that Celestia was not just connected to the Sun.
She practically was the Sun.
She also didn’t only move it! Among other things, she was able to conduct and channel arbitrary amounts of energy from the great thermonuclear furnace. She was a part of it and it was equally a part of her.
The only problem was: How do you control so much power, when it starts leaking through you?

And right now, Celestia’s fist… pardon… Celestia’s hoof carried a teeny tiny fraction of said power within it.

And once it touched the palm of Cthulhu’s hand…
Well…
It became Chthulu’s former hand.

The rest of his arm didn’t fare any better. Neither did the rest of his body…

After a few seconds, Celestia, eyes still shut, head still turned away and right foreleg stretched in the opposite direction, dared to slowly open an eye and look carefully around.

“Oh dear…”

Cthulhu’s smoldering remains (the few there were) rained sporadically into the sea.

Celestia’s heart sunk, her bowels already starting to grumble.
She grimaced, thinking about the true fight that was about to come.

“This is going to be a long year…”