"Have you decided yet, Luna Starlight*?"
"I'm sorry Nightmare. You're a good friend to me, and I really want to show my night to other ponies. But I cannot hurt my own sister."
"This is your final decision?"
"Yes, Nightmare. I will find another way. Surely somepony out there will listen to me."
"So be it Luna. If you will not help me, I will help myself to you."
"What... what do you mean?"
"Your anger and jealously have grown stronger, and I have grown stronger with it. I'm more powerful than you now. Once I take your powers as well, I can defeat your pathetic sister and stop her despised sun from rising."
"No... no... Nightmare, I won't let you do that!"
"No, Luna, you do not have a choice. Because Luna, I am you. We are the same pony."This sort of concludes the mini-story I had in my head. It began with
Nightmare Comforts Luna and continued with
Nightmare and Luna Stargazing. This little story ends with Nightmare's personality taking control of Luna's body - hence "transforming her into a wicked mare of darkness" - sealing Luna away for one thousand years until Twilight and her friends could remove Nightmare from Luna's mind.
But this leaves one final question for you to ponder: Is this battle mental or physical?
Additional Files: No magic version.Reuse: You are
not allowed to reuse this image without permission. If you post it on another site, I ask that you include a link back here.
The Nightmare Moon and Princess Luna characters and My Little Pony: Friendship is Magic are the property of Lauren Faust and/or Hasbro and/or others.* I have seen the name Luna Starlight used by other fan works. I like that name, so I reused it here.Thanks to DarCowAlways, NightmareMoonS and Skylark-Torch for feedback. 
`ChewedKandi has certainly gone out of her way to keep the vector community on the right path. Always making sure that her talents are infinitely scalable, Sharon has put her bezier curves to excellent use, and firmly anchored herself as an inspirational leader. We're absolutely delighted to bestow the Deviousness Award for June 2013 to `ChewedKandi. Congratulations, Sharon! Read More
Sta.sh
A secret I said I'd keep when I was little. The main reason I kept dreaming about having ponies see my night, and to show the same love they show my sister...yes...because of her. My journey begins here, and now. I'm going back to the waking world, then to my sisters side!