Part 2 of my Friday the 13th Special, this time actually released on the 13th!
Brotip: if you got a small bit of bile while reading the 'Cupcakes' fanfic...Don't read this.
Oh, and now canon. You'll see why.

Rainbow Dash fidgeted in her sleep, the cloud forming to her body, keeping her asleep as her body went on in bliss, but her mind fell into dark torment.
Rainbow Dash searched desperately for Fluttershy, but couldn't find anything in the debris and dust that obstructed her vision.
She heard moaning, the sound of a yellow Pegasus.
She ran over to where she heard it, and dug through the debris furiously, finally finding a wing.
"Fluttershy!" She tore into the debris more energetically, and ended up freeing the wing.
It fell out of the pile, blood spurting out of its severed end, the bone glistening in the dying embers of the flame that had consumed Fluttershy's cottage, the frayed nerve endings sending the muscles into spasms, causing the wing to spurt more blood, the meat and veins slowly getting forced out of the open end of the wing, sticking to the floor like a fine paste.
Rainbow Dash threw up as the wing stopped moving, the puddle of blood growing larger and larger, the wing finally dead.
The smell of blood and stomach acid made her throw up again, her eyes tearing as she sobbed with the pain in her stomach, hooves, and heart.
She heard the moaning again. She tore into the debris even more furiously, and uncovered a bloody stump, glass embedded into its emaciated ends.
"Fluttershy...no!"
Rainbow Dash dug around her, revealing the bloody mess of glass and wood splinters that impaled her.
Her old friend stood, shaking on her legs. Rainbow Dash gave her support, pulling her out of the mess that was once her home.
She immediately wished she hadn't.
Fluttershy's other wing tore itself in half, both segments flapping wildly, both sides spurting blood everywhere as Rainbow Dash's oldest friend died in her arms.
"Rainbow...I called out for you..."
The pony in question looked down at Fluttershy, eyes full of tears. She noticed then that Fluttershy wasn't looking at her.
She couldn't. Her left eye had a glass shard embedded deep into its milky, white core, blood and puss oozing out of the wound.
"Fluttershy...I'm sorry..."
Fluttershy's right eye remained stationary, a piece of wood embedded down through it, coming out through her yellow cheek bone.
"I...I'm scared...it hurts so much..."
The yellow Pegasus coughed up blood, causing her wing stump and half a wing to flap wildly.
At that moment, her half wing finally broke connection with the half embedded in the debris. The long, white nerve snapped, and the wing in the debris started flapping wildly, not wanting to die. Its meat was squeezed out, the unevenly cut bone causing it to flop unevenly, opening more wounds that caused the hole it lie in to bleed as well, the blood dripping down the feathers.
"Rainbow Dash...promise me...that you'll save Spike...he's somewhere in the house."
She looked around, searching for the baby dragon.
As she looked, Fluttershy coughed one last time, her unseeing eyes not changing as she passed into the void.
Rainbow Dash placed an ear to her heart.
"No...NO! Fluttershy...I'm...sorry..."
She sat there for what seemed to be too little time, rocking Fluttershy in her arms as the blood seeped out of her wounds, the smell of urine joining the smell of death as her bodily fluids were all forced out, creating puddles of liquid.
"Fluttershy..."
Rainbow Dash stood, and walked over to the same pile of debris she had found her dying friend in. She dug in it, careful to avoid freeing the yellow appendage, afraid that it would begin flapping and bleeding again.
As she worked, her tears blurred her vision, making it hard for her to recognize the baby dragon's purple arm.
She carefully dug around her friend's body, uncovering it bit by bit.
She retched when she found the rotting flesh, the dislodged scales that parted for the giant shard of glass that pierced him through the face, bits of brain left behind as she pulled the baby dragon off of it.
She laid down next to Fluttershy, and turned to leave.
Suddenly, she hurt a sputter, a buzz, and a gasp. She turned around just in time as an eyeless Fluttershy landed on top of her, darkness filling the eye sockets, her wing stub and half wing flapping wildly, spreading blood everywhere as it did.
"You said you would save him! First you let me die, and then you let him die!"
The cyan Pegasus tried to force Fluttershy off of her, her heart beating too fast for her mind to keep up. Her instinct an will to live pushed her to do what she had to in order to stay alive.
She grasped a large piece of wood that lay behind her and bashed her dead but living friend over the head with it, sending her crashing into the wall.
Crying, she walked over to Fluttershy as she rose, a thirst for blood filling her, a thirst for somepony to die and stay dead. She hit Fluttershy over the head again and again, each time deforming her friend's head more and more, splattering the yellow Pegasus' blood all over the walls, the skull caving in and stretching the skin like a balloon. Her head suddenly burst open like a melon, brains and blood splattering on the walls, floor, and cyan Pegasus, mixing with tears and sweat in a disgusting mixture.
Rainbow Dash threw the wooden rod away, stumbling backwards.
"What have I done...Fluttershy..."
She sat down and rocked back and forth, an insane smile twisting her features.
"Now she's dead. And she's not going to attack me. No, ma'am, no zombie Fluttershys here..."
As she closed here eyes, the world around her dissipated.
She opened her eyes to the black, charred interior of the Carousel Boutique.
Rainbow Dash frantically searched for Rarity, trying with all of her might to find the elegant, white unicorn.
She looked under mirror frames, under mannequins, and under countless piles of clothes, but couldn't find her friend anywhere.
Rainbow Dash was about to give up when a chill went down her spine.
"Looking for me, Rainbow Dash?"
The cyan pony turned in fear. The white unicorn's voice was cold and lifeless...
As was her deformed, crushed corpse.
"You didn't bother to come for me when I called your name while my spine broke. Look at what you have wrought, Rainbow Dash, through ignoring your friends as they died!"
The cyan Pegasus looked more closely at her dead friend. There seemed to be nothing wrong with her.
A sigh was about to escape Rainbow Dash's lips, relieved that there were no disturbing images here, when she saw what was truly out of place with the white pony.
It was the even whiter spine protruding from Rarity's white body, ribs stretching the place where the spine had left her body, giving her the image of a puppet, her inner workings being pulled out of her body.
As Rarity stalked closer to Rainbow Dash, her spine twitching as it was forced farther out, stretching her white coat. Rainbow Dash walked backwards, her heart beating furiously as she watched her dead friend getting slowly skinned.
With each step, Rarity's face was stretched a bit more, her legs were made a bit more formless, her skeleton was left a bit more uncovered, somehow keeping its form.
By the time Rarity was within striking distance of Rainbow Dash, her horn had snapped off, falling off of her body along with the rest of her skin, giving it the image of a puppet being used by this devil of bone, meat and organ.
Rarity's vital organs shivered as she walked, her lungs struggling to keep oxygen traveling through her body, the trachea vibrating with its final throes of life, the heart pumping wildly as it felt the body it depended on dying.
Rarity's white skull smiled at Rainbow Dash, the magical core of her horn leaking into its open teeth, the glowing substance creating a visible bulge as it traveled down the esophagus, into the stomach that lay beneath, quivering in its casing of meat and bone.
Rarity now stood right in front of Rainbow Dash, her bones clacking as she moved, the hooves clicking as they dislodged, bit by bit.
"Do you see what you have done, you rainbow maned freak? I'm falling apart!"
Even as the skeletons' jaw moved, the muscles fell away, meat slithered out in a fine puss, but the organs and skeleton stayed.
Her skeleton jiggled as it was bereft of tendons, cartilage seeping out from the unprotected joints.
Rarity's skeleton finally fell apart in front of Rainbow Dash, its bones clinking as it hit the floor, the organs squishing as they rolled around, vibrating with the quickly disappearing life.
Rainbow Dash ran out of the building, not wanting to spend another second with her friend's skeleton.
She looked to the dark sky, to whatever was making these horrible images. "What? Is that all you've got?!"
The insanity in her voice scared her, holding her still as the dark clouds descended upon her, fazing her vision out once again.
Her vision returned in a dark apple cellar.
The apple cellar of Sweet Apple Acres.
Applejack was on the floor in front of her, her golden mane cut and torn, her hat covered with blood, the stump of her hind left leg spurting blood.
A large chunk of foundation lie on her hind left leg, about five feet from the orange pony's body.
A trail of blood traced Applejack's desperate crawl to safety, the red trail jagged as the uneven bone dragged across the floor.
A stone in the head had ended her desperate crawl, splitting Applejack's head wide open, the red halo around her head joined by bone and brain.
Rainbow Dash turned to leave. She had had enough. She was going to run away, run where nopony could ever find her.
But then the cellar doors slammed shut behind her, and Applejack rose to her hooves, the stone rolling away, the stump of her hind left leg apparently not hindering her as she walked around Rainbow Dash, blood spurting from the area surrounding the broken bone.
She looked at Rainbow Dash, her left eyeball hanging out, a strand of muscle, vein, and nerve coming out of the darkness. Her right eye was replaced by total darkness, a darkness that Rainbow Dash wanted to enter to end her sorry existence.
Applejack's face wasn't the normal, round face, but rather, was rather flat, with a pink thing exposed on top, pulsing.
Rainbow Dash's friend walked forward, brain jiggling with each step.
She lowered her head, preparing to charge the cyan Pegasus. As she did, her brain fell out of the unprotected cavity in the skull, the spinal cord holding it as it swayed back and forth each time Applejack pawed the ground.
"You said you'd never leave Ponyville hangin', and now ah'm dead because you decided to leave Ponyville hangin'. Ah guess ah just didn' count, did ah? Well, ah'll show you how much ah count. It's time for you to die, Rainbow Dash."
Rainbow backed off in fear, her cyan coat covered with a fine film of sweat, matting the hair.
"Applejack...I'm sorry..."
The dead work pony didn't care. She charged, and Rainbow Dash rolled to the side, the wind from the carrion blowing past her at the same time the dangling brain made contact with her hoof.
Applejack crashed into the shelf of cider, the countless glass bottles smashing on the orange body that lay beneath them.
Rainbow Dash darted behind the adjacent shelf, cowering in fear, looking for an exit. Tears joined her sweat and Fluttershy's blood, forming a pool of pain and grief.
She stood, turning around to see if an exit had opened. She immediately regretted it.
The orange pony's empty sockets of darkness stared into Rainbow Dash's bright eyes. Her mouth hung open, a glass shard sticking out of her throat, blood dripping off of it, back into her decimated throat.
Rainbow Dash's rival tried to talk, her brain smacking the wood shelves, the glass shards embedded in the pink mass going deeper, drawing more blood.
The rainbow maned, cyan pony fell into the darkness where Applejack's eyes used to be, Her vision fazed, sending her deeper into her insanity, her hooves clicking as she held her knees close to her chest, shivering.
A light appeared in the dark, pulling Rainbow Dash towards it.
She moved towards the light, entranced by its heavenly, comforting glow.
The sight that awaited her was anything but heavenly and comforting.
Before Rainbow Dash, was the cloud mansion that was home to the cyan, rainbow-maned Pegasus.
The shaking pony walked through the door, an atmosphere of apprehension consuming as she walked, sending a shiver of fear down her spine.
She flapped her wings, blood and debris flying off as she flew up to her room.
She walked into the dark room, her eyes slowly adjusting.
When they did, the room became clear to her. Everything was normal.
Except for the noose hanging from the ceiling and the pristine piece of white paper that lay by Rainbow Dash's hoof.
She looked down towards the paper, and saw blood creeping across its surface. Her blood. It read:
You have a choice. You can end your sorry existence, or you can go back and try to save them.
She looked towards the noose, the gap creating a hole that distorted the world as she looked through it, showing her all of her friends' dying expressions.
Twilight, gasping for air as the tree branch impaled her, burning her intestines.
Pinkie Pie, her face melting off, her hooves scrambling at her face, tears and blood spreading everywhere as the flames consumed her.
Fluttershy, dying in Rainbow Dash's arms, the yellow Pegasus' eyes unseeing, debris impaling the white orbs.
Rarity, her elegant features contorted with pain as her spine was horribly removed from her back, the white bone splitting the white coat.
And Applejack, crying as a horrified Apple Bloom looked on, her face filled with fear and pain as the rock crushed her head, ending her throes of life.
Rainbow Dash walked up to the distortion, looking right through it into the void.
She swallowed.
As soon as her muzzle made connection with the rope, it ensnared her neck, chafing her as it tightened, pulling her higher up off the ground.
And then Rainbow Dash, gasping for air, hooves scrambling at the rope, came face to face with...
Rainbow Dash.
Rainbow Dash bolted upright on her cloud, shaking her head, freeing her mind of those horrible images...
She pulled herself off of her thundercloud of nightmares and berated herself for ever believing a dream.
It was the first time she had seen the images.
Unfortunately for the (currently) mentally stable, cyan, rainbow-maned, happy Pegasus, it would most definitely not be her last time seeing them.
About a month later, an explosion interrupted her sleep, lighting the world up with its aimless light.
--------------------------------------------------------------------------------
And thus ends the Friday the 13th Special Chapter.
By the way, if I didn't make it obvious (not sarcastic, I actually suck at referring to the story within a story...Leonardo DiCaprio is disappoint...) the ending refers to Rainbow Dash's part in the second chapter, when Peter Roose actually arrives in Equestria.