I promise I won't try to stop you!
Today would have been like any other. Yes, the day would have started with Celestia getting her morning cup of tea and breakfast and Luna with her pineapple, then they would go about their usual, mundane business. However, the only normal thing that happened that morning was Celestia getting her tea before an infuriated Luna entered the room and broke Celestia's teacup with her scowl.
"-sigh- Lunaaaa, that was my favorite teacup..." Celestia groaned. Somepony woke up on the wrong side of the bed today... or I suppose in Luna's case, she's had a very long night and is in desperate need of sleep.
Luna then proceeded to eat the top leaves off of a poor, unsuspecting pineapple and then took a bite out of the plate it was formerly sitting on.
Very, VERY desperate need of sleep... Celestia concluded within herself, mouth agape. After an awkward moment of silence and some more questionable diet choices from the younger sister, Celestia dared to speak.
"So... how did your night go-"
"I SWEAR SOMEONE IS GOING TO GET EXECUTED TODAY!!!!" Luna screamed in the Royal Canterlot Voice right in Celestia's face.
Celestia rubbed the pain out of her face and ears for a moment before actually comprehending what her very tired and probably delusional sister just said. "W-wait, what about execution? Who's dying? Huh?"
"I don't know who DARED to turn my room upside down, LITERALLY UPSIDE DOWN, but when I find them I WILL HAVE THEM BEHEADED FOR THEIR CRIMES AGAINST THE CROWN!!!" Luna yelled out again.
A lesser pony would’ve gone deaf by now. Far in the distance, Twilight was wondering who committed a crime against the crown and if she should write a letter to Princess Celestia about this possible new threat…
“L-Luna? You do realize we don’t do that anymore, right? I thought we had this conversation already,” Celestia asked with concern for Luna’s quickly dwindling sanity.
“Oh, right. Then I have the opposer hanged!” Luna corrected herself.
“Lunaaaaa…”
“No to that too? How about poisoning?”
“LUNA! I MEAN THAT WE DO NOT EXECUTE ANYONE ANYMORE!!! THERE IS NO CAPITAL PUNISHMENT!!!” Celestia yelled in Luna’s face, giving her a taste of her own medicine.
It was Luna’s turn to rub her ears, but not because of eardrum pain. “I’m sorry, did I hear you correctly? There must have been something in my ears. Did you just say executions are no more?”
“I said it and meant it Luna. Even if we still did executions, being on the receiving end of a prank is hardly punishable by death!” Celestia tried to reason with Luna.
“That never stopped us in the past.”
“These are different times! We can’t just execute anyone who slightly peeves us! That’s just plain murder.”
“But we’re royalty,” Luna tried to justify.
“And we are not exempt from our own laws! I’m sorry Luna, but NO! You will NOT be executing anyone,” Celestia sighed as she left the room to get another teacup.
“Hmph… fine,” Luna begrudgingly obeyed.
The next day would’ve been an otherwise peaceful and pleasant day, but a certain draconequus had a death wish for himself.
“Ah, picking on little miss Moody Moon is always such a fun pastime! She’ll LOVE what I’m about to do next!” Discord schemed.
Discord had snapped himself into Luna’s room while she was sleeping and proceeded to snap her horn and wings away. Then, he moved her bed onto the edge of the balcony.
“Now to hope she wakes up on the correct side of the bed!” Discord quietly laughed as he waited at a (somewhat) safe distance for Luna to wake up.
Right on cue, she woke up with a dramatic yawn and didn’t bother to take off her sleep mask (the only reason Discord’s prank didn’t fail the second he moved her outside her dark bedroom into the setting sun's light). To his delight, Luna rolled out of bed to be met not with the floor beneath her hooves, but just began falling.
“What the- AAAAAAAAAAAAAAH!!!!! OW!!!!” Luna screamed as she fell who knows how far to the bottom of the mountain Canterlot Castle was set upon, leaving a massive Luna shaped crater beneath her. Perhaps it’s for reasons exactly like this her balcony shouldn’t be situated outside the Canterlot ground borders…
Discord meanwhile couldn’t contain his laughter, nor the urge to really rub in his prank to Luna as she lifted her mask to see what the hay just happened.
Then she saw him.
“Discord?”
“Moonbutt.”
“DISCOOORD!!!! YOU’RE AS GOOD AS DEAD!!! FORGET THIS STUPID ‘NO EXECUTIONS’ RULE!!!! I SENTENCE YOU TO DEATH!!!!” Luna screamed with uncontrollable rage.
“Oooh, I’m so scared!” Discord mocked Luna while she rubbed the dirt and pebbles off of her body.
“As you SHOULD be…” Luna growled.
Luna began to approach him very predatorily with an axe in her mouth. Where that axe came from is of no concern to anyone, except maybe Discord.
“You will give me my wings and horn back, and then you will DIE!” Luna commanded rather clearly for someone speaking with an axe handle in her mouth.
“Fiiine, but only because I’m sure Celestia would have my head too if I didn’t give them back. You still need to raise the moon after all,” Discord complied as he snapped her horn and wings back on and teleported them back to her balcony.
Everything was put back in order and Luna brought forth the night. But while she did that, Discord took the liberty of getting the hay out of there before Luna could do well on her death threat. Luna turned around to find him gone and responded accordingly.
“AAAAAAAGH DISCORD!!! YOU CAN RUN, BUT YOU CAN’T HIDE!!!”
As it turns out, he can hide. Very well might I add. The pranking didn't stop, but Discord was wise enough to keep his distance whenever the pranks went down and just watch from a safe distance then high tail it out of there before she spots him.
"Luna, don't you think you're overreacting just a little bit? Just a little? Maybe?" Celestia tried to reason with Luna (some poor souls never learn).
"Forgive me if I'm wrong, though I most certainly cannot be on this matter, is Discord a menace to society and tried TWICE to usurp the throne and reign chaos eternal? He could do it again at any turn! His only downfall is his love of gloating at his success long enough for us to pew pew him with the friendship laser and petrify him for a thousand years! But do you know a more permanent solution to ridding the world of his scourge? BEHEADING WITH AN AXE!!!" Luna ranted before completely losing it.
"By those accusations, doesn't that mean you ought to be executed for, oh I don't know, attempted domestic murder and usurping of the throne whilst trying to bring NIGHT eternal?" Celestia pointed out.
"W-we don't talk about that! It's not the same thing. I'm your sister! And a princess. Siblings are bound to get into little scuffles. DISCORD IS EVIL!!!" Luna defended herself.
"Uuuuuugh, okay you know what Luna? Fine! Just go for it," Celestia finally caved.
"Wait, really?"
"Yes, I won't even try to stop you."
"... Are you sure about thi-"
"Oh so NOW you choose to be sane?"
"I-I just didn't think you'd actually go for-"
"Oh look here he is!" Celestia said as she yanked him from the mysterious realm that is called "off screen" and shoved him in front of Luna.
"Now that's just rude. I was taking a shower you know," Discord humphed as he snapped away his shower cap and shook off the chocolate milk from his body.
"Well Discord, prepare to die. Any last words?" Luna asked.
"Well actually-"
Luna eyes glowed white as she swung that axe above her head with an annoyed Celestia behind her and lopped Discord's head off his shoulders.
A moment of silence for the loss of a great and chaotic being...
"Why is everyone being so quiet?" Discord asked as he opened his eyes and placed his head back on his body. "Honestly, that didn't hurt as much as I thought it would. Heck, it didn't hurt at all!"
"W-What?! But how did you-" Luna was interrupted as Discord answered.
"I'm the Lord of Chaos! I'm made of PURE chaos. Did you honestly think you could kill me?"
"... You knew this Tia, didn't you."
"Yes, yes I did," Celestia responded smugly as she sipped on a cup of tea (also from "off screen"). "I believe a truce is in order?"
"-siiiiiigggggh- Truce, Discord? It seems I have no other choice..." Luna begrudgingly offered.
"I gladly accept!" Discord said as he shook Luna's hoof vigorously.
Finally, FINALLY the day went normally! All was calm and peaceful in Canterlot and absolutely nothing was out of the ordinary! It's normal for cakes to come flying towards your face right?
"What the -SPLAT!!!-" Celestia failed to finish her statement as a cake landed squarely on her face.
"HUZZAH!!! A splendid shot my friend! Right on the nose too," Luna clapped as she and Discord came into view.
"I told you this would be fun!" Discord said as they hoof-bumped.
"Pranks are much more fun when you aren't on the receiving end of them. Oh oh! What should we do next?" Luna acknowledged with excitement.
"Heheh, I'm glad you two are getting along now eh- hold on... where did you get this cake?" Celestia asked with suspicion.
"The fridge. Why?" Luna asked back.
"What shelf did you get it from?"
"I don't see what that has to do with anyth-"
"JUST ANSWER THE QUESTION LUNA!!"
"I don't know! I think it was the middle shelf."
"Was there a sticky note under the plate?" Celestia asked, her mood growing dangerously dark for a Sun Princess.
"I don't know! Discord, did you see a sticky note when you got the cake?" Luna asked, looking to him now.
"Ah yes, I did. It said, 'Princess Celestia's special cake. Please do not touch or eat. I'm looking at you Discord! Thank you :)' As if you thought I'd listen! Ha!" Discord recalled, not noticing Luna face-hoof then make a slow getaway and distance herself from him. By the time he did notice, Celestia's mane had already turned to flames and her eyes glowed like fire.
"Ooooh, Sunbutt's a little fiery isn't she. Get it? Hahaha!" Discord laughed, clearly unaware of the danger he was in right now.
"Discord, run!" Luna insisted.
"Why?"
"Oh please, you think I have a temper?! You've just infuriated the princess of a literal giant ball of FIRE!!! You're gonna have a hard time finding all the pieces of yourself this time. So trust me. RUN!!!" Luna explained as she quickly flew out of the palace at Sonic-Rainboom speeds, breaking all the windows in her wake.
Realizing just how serious the situation was, for once Discord listened and high-tailed it out of there with an angry ball of flames just behind him.
"DISCORD!!! I SWEAR WHEN I CATCH YOU I WILL DESTROY YOU SO THOROUGHLY YOU'LL NEVER RECOVER!!! AND. IT. WILL. HURT!!!" Solar Flare screamed as she chased down Discord for an undetermined amount of time.
And that is the story of how Equestria went down in flames.
Author's Note
Thank you guys so much for reading! This was a silly idea I came up with while commenting on another story about how Luna may execute a very annoying and mean pony even without Celestia's permission (and that even Celestia might be fed up enough to just be like "You know what Luna? Just go for it..." which inspired this entire story LOL).
I hope you guys enjoyed! Do the stuff you know to do if you want to and have a great day! 
