This is a story that LOOSELY ties in with "Into the Everfree Forest" and "Into Ponyville", so if you haven't read either, don't worry about it.
Disclaimer: I do not own MLP, just Cinnabar and this story.
My name is Cinnabar; leader of the Cult of Discord. What is the Cult of Discord? To understand how we came to be, you must understand my past.
I am a unicorn and distant descendant of Starswirl the Bearded. My cutie mark is the alchemical symbol of mercury, a deadly poison often used in magic, which I am an expert on. I was a magic apprentice at the Canterlot Academy, but I was thirsty for knowledge; so much so that the books that were given to us at the academy did not satisfy my needs. I wanted to learn more outside of what the school taught us; I wanted to learn... the forbidden arts.
I scavenge for many sources, even from stealing, to learn all I can about the dark magic that my teachers had forbidden me from learning. I learnt about Discord, the spirit of chaos and disharmony and of elements that countered the so called "Elements of Harmony"; Deception, Despair, Greed, Cruelty, Disloyalty, and the most powerful element of them all, Hatred.
I had learnt to use these elements to make my magic even stronger; I had even created a spell in which I call "Discord's Fire"; much hotter than mere flames and can cause permanent damage to my opponents; I had even once blinded an earth pony colt with my spell. Eventually, however, I was caught using these dark elements in my spells and was kicked out of the academy.
It was then I had given up on worshipping Princess Celestia and the Elements of Harmony and swore my allegiance to Discord and the Elements of Chaos. I gathered other ponies to follow Discord and together, we created a clan that embraces chaos and swear off Honesty, Laughter, Generosity, Kindness, Loyalty, and the weakest of all the elements, Friendship. Together, we shall bring chaos to Equestria and summon back Discord to rule us all.
Well, if you want this story to continue, please R&R.