Scootaloo is the bestest and greatest crusader. Sweetie Belle is nothing but a dog's chew toy--one of the squeaky ones--given life, and Apple Bloom just sucks.
Everyone's a changeling. You, him, her, that. If it moves, it's a changeling. If it breathes, it's a changeling. If it's alive, it's a changeling. And Chrysalis is utterly sick of it.
The Crystal Empire is old and strong and arrogant. It is the sole domain of ponydom outside the Sisters' rule, a preserved reminder of the days that passed long before the foundation of Equestria. And it teaches its lessons well.