Luna cannot be Nightmare Moon. Celestia has decided, and the royal historians are ready to sign it off. She just needs one more pony to agree, but she isn't buying into it. Who is she, and why can't Celestia move without her approval? What does she have against Princess Luna? What's with her funny name?
The scales must be balanced. Justice is no respecter of ponies. Justice tells only the truth, and loyally defends the just. Justice is fair, but woe to those who grieve her. Mercy is kind. Mercy softens her blows, and defends all, regardless of what is deserved. Mercy gives and forgives. How does a pony draw the line between Justice and Mercy?

This is the first fanfic I've ever posted, but far from my first story/writing. Don't be too gentle.