Nightmare moon summoned a "spirit" from nowhere because of being bored and mentally unstable. Then she trained him into a faithful follower. But things screwed up when she came back.
The aftermath of Celestia's old mistakes appeared and...(Coming)
And the invasion of changelings...(Coming)
We all have to pay for what we have done. But these ends well.
P.S. sex tag for mentioning and this story has multiple OCs.
And I'm sorry this is my first story, I'm afraid I can't quite handle this.