I really liked this idea so, I'm going to give it a quicker shot. The miasma of Princess Luna's hate, frustration and anger has been cornered. That inky black energy clump is right there. Ready for something to be done with it. If we don't, then it might try finding another host, just like it did with Rarity. The premise is simple: We all absorb the essence that created Nightmare Moon and try to use it for good. Why? Well, it's emotional energy right? So, we just have to process it like normal emotions. Control them and work through them until they're manageable. Right? It's possible, not all of us will survive. Well, as heroes of the land anyway...
I'm willing to do this with my Bat Pony OC again. I could restructure his reason to be to show others that bat ponies can do good things for Equestria as well.