Fluttershy doesn't want to go through the pain of loving someone, and eventually having to let them go. So instead of loving, she commits to killing. Anypony she falls in love with, or falls in love with her, she brutally murders, no matter how innocent they may be. Of course, no one suspects a thing from the kindest pony in Equestria. But when a certain mare shows her the joy of love, she opens up about everything.