When she awoke from her place in the wildlands, all Chrysalis could think about was revenge. Against Celestia, Cadance, Twilight and all of her friends.

She thought she had been subtle. But perhaps not enough; she knew how they thought now. What things they looked for in a person. She would lure them in, deceive them in fullness, and feed.

A plan in place, Chrysalis begins her long road to revenge, seeking out the weakest link in the entire chain. The one most vulnerable, most willing to believe the best in others:
Fluttershy.