Loneliness. That's all Crimson feels after Discord reverts back to his old, chaotic ways. Everypony knew this was happened, but Celestia kept telling them nothing was wrong.
Lies, all lies. Celestia was stalling, maybe even trying to convince herself.
Because of this, Crimson Fang, a batpony filly, is all alone. Everypony she knows is gone, and all she can do now is try to save them, or give up. And giving up looks pretty good right now...

Idea, and it came from a photo...
Yes, this is the third second story with her in it.
SPOILERS!!!