Golden eyes and a large, curved front tooth were the first give-aways. I was changing and I knew it. I was changing into the monster from my dreams, no, my nightmares.

That wasn't all though. He left me a last little gift as he called it, sending me into a deep slumber only to awaken inside the room of a large white horse with a horn and wings. And she did not look happy.

Adjusting to a land filled with ponies is hard, adjusting to a land filled with ponies whilst you can feel your body and mind change is harder.

I had hoped that if I write down my memoirs I would escape him, escape his influence and his power and his alterations.

How wrong I was. Now I can only recite my tale as I feel the last shards of my sanity leave me. As I feel him beginning to take over.

You can find the artist of the picture at: Poor Yorick
I'll add tags/characters later depending on what I plan for this.

The spirit of madness learned his lesson after those pesky ponies re-sealed him in his stone tomb. This time around there would be no princess Celestia, no elements of harmony, and most important of all, no magic of friendship. His plan was to tear the kingdom apart at the seams, and this time, his scheme was perfect. An infinite jest that was to be the jewel in his chaotic crown. Equestria would be torn asunder and his sweet insanity would rule the land once again until the end of time.

After failing to stop Nightmare Moon in the ancient castle of the pony sisters, Twilight Sparkle is left with a scar that will permanently change the rest of her natural born life. As Twilight recovers from her ordeal, she finds that she is left with a difficult choice. Either live her life as a lie or sacrifice her innocence to protect the ones she loves. The path before her is set and she must now walk it alone. The sands of time continues ever onward, with everyone already trapped in its muddy depths. The sun will rise and the sun will fall. Waiting for its call, Death awaits for all.

Tags, rating, and characters can change.

Art created by:
http://cuteskitty.deviantart.com (top)
http://ventious.deviantart.com (bottom)

I just put the two together

One cold autumn night, Twilight Sparkle lets in a pale and weary traveler into her home. When she accidentally discovers his dark secret, she is assaulted by him, and is left to die... When she woke up, she finds that she has been turned into a Vampire, an ancient enemy of Equestria last seen during Nightmare Moon's Rebellion. She now walks the thin line between life and death, sustained only by the blood of others.

Her friends now race against time to find a cure for this ancient curse, and stop the Vampire who infected Twilight, before he can create a new army of Vampires to conquer Equestria. Otherwise, Twilight will join the forces of evil and darkness, as the Bride for the Lord of Vampires. They have to work quickly, as every day passes, Twilight's thirst for her friends' blood increases...

In an alternate reality, Discord found his love of chaos came in handy for babysitting young foals. For two thousand years, since he and the princess' were kids, he's babysat nearly everyone in Equestria. Now he's babysitting the cutie mark crusaders, and while he does he recounts with them his many babysitting jobs of your favorite characters as fillies, one by one.

Twilight Sparkle: magician, scholar, bearer of the element Magic, and most of all, friend.
A bat, a book, and a bite can change so much of that, and bring darkness to her heart.
Can you keep your friendships when you might hurt those around you?
If you want to hurt them?
Bloodlust can bring an end.

The supernatural: Ghosts, zombies, werewolves, spirits... vampires...

Twilight Sparkle always thought that the supernatural was just a bunch of superstitious nonsense, just some scary stories to tell around a campfire. She couldn't have been more wrong.

After an occult ritual gone horribly right, Twilight finds herself among the ranks of these so called 'myths', whether she likes it or not. Due to the same force that changed her, dark shadows have begun to spread across Equestria, bringing to life these ancient fairy tales. And Twilight might just be the only one that can stop them...

For better or for worse, Twilight has been changed. Will she embrace this dark gift and become the hero Equestria needs, or will she eventually succumb to temptation and become the very thing she fights?