Nightmare Moon looked around her treehouse critically. Streamers- check. Pointy hats with tassels- check. Balloons blown up in fun animal shapes- check and check.
She gave a satisfied nod.
More than enough to top the parties she hadn't been invited to.
Oh, she'd heard about them all right. She'd heard about how the first one was just terrible, and the second one was much better, and she was just miffed both because she hadn't been invited, and the massive particle collider she needed to create a black hole to destroy the Earth had been confiscated due to overdue credit card bills.
She was peeved.
"I suppose this might be an okay party," Rainbow Dash said gently, encouragingly, trying to make Nightmare Moon feel better about being excluded.
She noticed Apple Jack rolling her eyes off in the corner, and tried to ignore her. She was such a party pooper. She'd left last time early just because there'd been a slight accident.
Rarity was already dancing to the music in the corner, and Fluttershy was bobbing her head in time with the music. Two of her hooves were bandaged.
Twilight Sparkle loomed in the doorway, gazing in at them distrustfully. She didn't like Nightmare Moon sometimes, mostly because her first impression of Nightmare Moon had been a bad one just because Nightmare Moon tried to kill her and all the Earth. But she supposed she was just being cruel here.
"I like what you've done with the place," Twilight Sparkle said tentatively.
"Ha! Do you really?" Nightmare Moon said. "I sincerely doubt it."
"No, please, I do. I just… well… What can I do to put bygones behind us?"
Nightmare Moon scowled. "You can get the cake from the refrigerator."
Twilight Sparkle opened the refrigerator, but the act of opening it sent it tumbling down toward her, and it crushed her body, cracking all of the bones of her cervical and thoraci spine and making blood boil up in her throat. She coughed violently, choking, tasting the iron substance as her lungs filled with it during her spontaneous hemothorax due to her shattered ribs lodging into her lug tissue and tearing it.
Rarity saw this and screamed and screams, and tried to flee, since she feared this would be a contagion of accidents, but she careened into Fluttershy, sending them both careening head over heels into the fireplace, where flames lit their tails and seared in an instant over their soft hides, sending the smell of pony thick on the air. They screamed, their skin blistering and giving off pungent exudate as their third-degree burns grew worse and worse. They danced wildly, trying to put out the flames, and crashed into the screaming, horrified Nightmare Moon.
Nightmare Moon tried to dash out the door, hoping to reach water, but then Pinkie Pie was coming in. They crashed into each other, shattering Pinkie Pie's ribs and jamming fragments of bone into her lungs, and up into her soft brain matter. Subcutaneous tissue bubbled out of the wound and splattered across the ground, and her hooves slipped across it.
In the meanwhile, the burning Fluttershy and Rarity both had a problem. Their burned flesh was peeling off in bloody layers as the flames charred them. The fire had spread over her hide, as well, and the horrified Rainbow Dash tried to get away, but she slipped on the carpet, and her tender throat crashed down onto the sharp canines of Twilight Sparkle's teeth. Twilight Sparkle was still choking and she bit instinctively, ripping at the flesh of Rainbow Dash's throat. Flames boiled up on all sides of them and caught a number of jars of alcohol, sending them hotter and brighter. The air was filled with coughs, gurgling ,choking noises, and screams, and the floor an elaborate finger-painting of subcutaneous tissue splashed over blood, over the black, tarry substance of Twilight Sparkle's crushed bowels.
Apple Jack waited a few minutes, hoping things would pick up, but at last, she had to admit it even to herself: this party sucked. She sighed and trotted out the front door, leaving the burning treehouse and screaming, lame pony behind her.