Luna and Twilight take a stroll in the gardens of Canterlot Castle, until the two eyes of twilight are bruised and have to wear a medical band in the eyes. Luna knew what had happened, thinking it was her fault, she became very emotional and sad.
Note: Twilight is a unicorn in this story.

link where I got the background: http://www.movieweb.me/twilight-sparkle-library-background.html
Twilight vector link: http://sulyo.deviantart.com/art/Twilight-Sparkle-320397233
Princess Luna vector link: https://www.deviantart.com/90sigma/art/Princess-Luna-Reflecting-2-341763341
Nightmare Moon vector link: https://www.deviantart.com/90sigma/art/Upset-Nightmare-Moon-Redux-375185142

Warning: This story contains Yandere Luna/ Nightmare Moon, so if you don't like gore and see a character or Luna and Nightmare Moon acts like a Yandere, don't read and not dislike this story.

Luna always knew that Twilight was special. And how could she not be? After all, Twilight helped her reunite with Celestia and helped her with Nightmare Night.

And now well after the end of Nightmare Night, Twilight and Luna have become great friends and even began to spend time together, until Luna started to develop loving feelings for the purple unicorn.

But there are five mares and a princess who are much closer to Twilight than she is, and it causes her a feeling she would never have imagined she would feel again: jealousy.

So, determined to have Twilight for her, and only for her, she decides that she will eliminate them. But the jealousy she feels is only the beginning, because as the jealousy grows, somepony who was defeated a one year ago, will return, and will make sure to have Twilight just for her.

I don't even know the 'official unofficial' ship name for Twilight Sparkle / Nightmare Moon.
- Twightmare Moon is funny? But I don't think most people would go for it.
- "Moonlight" is a fanname for a minor character late-ish in the show (s5?)
- bats (who has never seen this story) suggests "Spicy TwiLuna" and "Spicy Tuna"