Sometimes the worst feeling in the word is the feeling of forgetting someone. That feeling you get when you can just barely remember someone important in your life, someone you once loved or idolized. Lightning knows that feeling all too well.
He’s been feeling it for the past decade. As the years slowly tick by he can feel himself forget more and more about the ponies he once called friends and family. He despises the feeling. He wished he could get rid of it forever.
So he does.
Heavily inspired by Monochromatic’s Injuring Eternity, go check them out!
If you're talking about literal light from the sun, "Sun's Light" shouldn't have any capitalization as it's not a proper noun. If I'm wrong, ignore this.
Got some redundancy here. First sentence is kinda odd too. It might flow better if you were to phrase it something like "The castle was devoid of tapestries, stained glass, but most damningly, life. That is, except in a single tower" Then add some spooky descriptions like "overlooking the Everfree" or something.
Neither Tower or Light should be capitalized. They're both regular nouns, not proper nouns. Unless Light is the name of a spell or something.
I also noticed you do the same thing with "Castle." Unless used in a name like "Castle of the Two Sisters" castle shouldn't be capitalized.
Ooh, a new area where humans used to live as well? Color me interested.
These last two sentences are worded quite oddly. Especially since a sentence needs a direct object and a verb, and the last one is missing a direct object. Maybe rephrase it like "His eyes, usually a dark emerald green, but now a glowing white, were peering around pensively/inquisitively at his surroundings."
Would change "anywhere" to "everywhere". Fits better with the surrounding sentences.
Now I've seen a being of this concept in a lot of fics, but I particularly like how you introduced this one.
I've seen a ton of people misuse semicolons. Kudos on you for getting it right.
Add one more period to make the ellipses proper. Like this: "Right...?"
Why is Faust italicized and knows not? Since "Faust knows" is one complete phrased they should either be italicized or not italicized together.
You used anyways twice in one sentence. That's a bit repetitive and kinda messes with the flow. Knock off the second one maybe?
This last sentence is worded oddly.
Tower shouldn't be capitalized.
See above.
Altogether, nice. It's a very promising open, and has a good amount of vague. Enough to keep somebody reading. Not too many errors, especially for the first draft on your first story. I will be following this story till it's completion.