Once, there was a pony with a dark heart. Soon, it turned darker and darker to the point of no return, and his dark heart caused destruction. It was sealed, but, his black heart yearned for bittersweet revenge.
Centuries later, strange things started happening when Equestria seemed to finally be at peace. Ponies started to disappear and important items were stolen. Only a few ponies saw the connection. It's a shame they didn't act sooner, otherwise, this all could have been avoided.
Finally decided to take the plunge and upload your first story? Let's take a look.
Don't forget to tag the story with categories. This helps people find the story when searching.
A few spelling errors:
You seem to understand that each character's dialogue should go on a new paragraph, but let me make a suggestion. It looks better to only put speech at the beginning and/or end of a paragraph, rather than breaking it up in the middle. Also, try not to put pieces of action that belong in one paragraph on the tail end of the previous one - i.e. "Twilight seemed uncertain." (plus some spelling errors marked in red)
Would look better as:
Step one for improvement would be writing this on an actual word processor. This would catch most of your spelling mistakes. If there isn't one installed on your computer, use Google Documents.
It's one of the better first stories I've read, discounting the spelling issues. Keep going - practice makes perfect!
It's a little rough around the edges, but an interesting concept. I wish you the best of luck in your future writing endeavors!