Loyalty from Above and Beyond the grave

It started with what appeared to be a common cold, something that Rainbow wouldn't let stop her from being with her friends. It got worse unfortunately. First, she started becoming increasingly aggressive...

Dash was furious, that, that salamander, had made Fluttershy cry... "Buck this..." Rarity gasped at her language. "I'm going in!" Before bolting in and delivering a flying hoof to the snout while screaming, "GET... OUT!!!" At the top of her lungs.

The dragon turned to her, snarling. "YOU DARE?!"

"Yeah, I dare alright, you made Fluttershy cry! NOW COME AT ME, YA NEWT!" The dragon roared in her face. And was surprised to see the pony still floating there, glaring. Tuo everypony's surprise, instead of attacking, the dragon began laughing.

"heh, hehehe, HA HA HA *snort* ha ha! A pony, a pony of all things, and a mare no less, has the gall to trek up this mountain, kick me in the face, insult me, and demand that I leave? This is worth my weight in gold for the sheer audacity of it! Very well, rainbow pony, I will humor you request..." and gathering his hoard, flew off into the wild blue yonder.

"ARE YOU BUCKING INSAINE! WHY WOULD YOU DO THAT?" Twilight was incredibly concerned for Rainbows mental health.

Pinkie held up her whooves. "Aliens."

"Pinkie? Y'all be making less sense than usual, can you explain?"

She merely held her hooves up again. "Shark week."

Dash didn't care. "See you guys, I'm heading back to my nice, comfy, cloud bed."

Later, she developed a ravenous appetite...

"Faust, mother of Celestia, she's eaten more than Pinkie..." Aplejack watched with awe.

"And she's still not stopping!" Rarity was sickened by how Dash attacked her food, not even coming up for air.

"She might just outdo Celestia's legendary cake binges..." Twilight couldn't comprehend where all that food was going.

When she started puking blood, however, she knew she was in trouble, but kept on going anyway...

Discord was impressed, and even a tad fearfull at the ponies defience. She had doubled over at one point and vomitedva large amount of blood, yet not only did she fight through the pqin and blood loss, but also his attempts at mental manipulation, on rage alone, before something flew overhead and was cauhht by the polychromatic pegasus. It was the Element of Loyalty. Discord barely had time to mutter 'oh, poo...' before getting the buck Harmonyed out of him, petrifying him.

Dr. Whooves was bored, it was his turn to pony the reception desk, and nothing had happened today...

*ding*

Rainbow had just walked in the door, looking incredibly pale, before collapsing on the floor, flecks of blood spewing out her mouth...

"Oh buck! We got us a code 42-D ponies! Move it!" Several nurses came running in.

"Faust, what happened to her!"

"She ain't breathing, no heartbeat either! get the shock paddles!"

Attempts to revive her were unsuccessful...

Which brings us to today...

"We stand here today, to witness the death of a hero, a mare who would, - and did - stick with her friends, even in the face of Discord himself... yet a few week later, she was struck down by what could only be rationalized as curse from the same foul beast she and her friends defeated. I, Princess Celestia, and every citizen of Equestria, bid you Faust speed, Rainbow Dash, you rekless mare..." With the utmost silence, the coffin was lowered into the Canterlot gardens, beneath a prismatic tombstone, inscribed with the words 'Rainbow Dash, one of the Six, and taken from us all to soon...'

However, the 'curse' as they put it, was not yet finished... as time went on, her body began slowly changing, her colors dulling, everything in her body slowly undergoing reconstruction, her appearance becoming more... predatory.... as her thoughts devolved into a feral slurry of emotion...