What if Princess Luna knew Nightmare Moon years before her transformation? What if she grew to trust that figure that she saw as a sister and best friend, not knowing that she would one day become that monster?

This is a Comment Driven Story, so I'll need lots of ideas in the comments to write the rest of it. I want to finish it at ten chapters (maybe I'll have an extra one for good luck!), but each chapter will be 1.5k-4k words long, so I might be able to include more than one idea per chapter.

Violence for the end of the story. (You should know what happens. If not, you shouldn't be on this website.)