So I am quite new to mlp fan works, and honestly the show itself. After catching up with the series I decided to try my hand at fanfiction for it, but it's been... ill received so far if the downvotes are anything to go by. I was hoping that someone might help explain why that is, that way I can make it betterIt the future.

http://www.fimfiction.net/story/214937/the-guardian-of-darkness

3619979 It might not be the story itself, I think the reason for the downvotes was because most people don't like the whole black Alicorn thing. Back in the early days of the fandom, Alicorns were made by everyone and they were usually black in color with some designs that were red. Over time people got annoyed by them and hated them. For your story, I don't think anyone really hates it, but they don't like the black Alicorn thing.

I read it and like it though.

3619979
OCs are hard enough to make good, alicorns are even worse and will probably get your story thumbed down just for mentioning an OC alicorn especially one that's some generic color like black or red.

3619979 I'm going with what everyone else has said so far. 3620018 3620804

Also, a few things.

This sounds like the narrator is introducing a play. Not that it's a bad thing, but straight up telling us what's going on instead of showing us what is going on is kind of...

...boring to read.

Not only that, but you need to go through this and just hit it a bit.

kept safE by his birth from the disease.

Errors like that...

Plus, the factions aren't capitalized. They're just earth ponies, pegasi* (plural for a pegasus), and unicorns.

In addition to those errors, you don't use proper English grammar in the sense of quotes.

You use the dialogue tags, but not the quotes?

Quotes are what makes the world go around, not burn to the ground.

He's here. The voice from before spoke once more in the sweet and motherly tone.

I told you he would come. A second voice replied, sounding like a proud father who had just seen his youngest child take a step.

You can always trust somepony like him to answer the call when they are needed. The third voice sounded like that of an old man, full of wisdom from a long life.

Welcome. The three voices spoke in tandem inside of the Earth pony's mind.

That should be:

"He's here."

"I told you he would come."

"You can always trust somepony like him to answer the call when they are needed."

"Welcome," the three separate voices say, their tones speaking volumes inside his mind.

See how I put it? I took out all the other stuff because you don't really need it. Also, keep in mind that you can use pronouns instead of "earth pony" to describe your character. The alicorn says syndrome (I think that's what they call the noun usage issue) is not a good way to show your characters off. I learned that the hard way.

There's a ton of other things such as prepositional phrases being misused and other errors that I think you can find for yourself. If I told you all the errors, you would never learn what happens and why it happened. I mean, that's how one learns: punching, slapping, and ripping apart your fan fiction until you reach as close as you can to perfection.

I think that's why you're receiving the voting ratio that you have at the moment.