Fluttershy is the Butterfly of your heart. She gives you reason to live, to forget all the horrible, terrible things you had to live through; but now she's gone, called away by Princess Celestia to help a hoof full of settler ponies to inhabit a new continent on the other side of the world. Now the darkness that her love kept at bay comes creeping in, and now you have no reason to fight it.

Warning: [spoiler]Grimdark and the disturbing imaginations of a very sick and twisted mind, (also a writing experiment, so bear with)[/spoiler]

(Gory bits don't start till chapter 3)