Fluttershy doesn't realize exactly what she's getting into when she becomes the bearer of the Element of Kindness. Thus, when the Elements are used to turn Discord to stone, she is horrified and plagued by nightmares... nightmares of the power she wields but never asked for, nightmares of how far she might have to go, nightmares of a legacy she never wanted. She's going to have to take major steps to soothe her guilt. Befriending Discord is only the beginning, it seems.