Sunset Shimmer is lost in a world that she can't move on from. Twilight Sparkle is lost in a world that moves on without her. Together, they each try to find their way again.
Sunset Shimmer has never needed anyone or anything - she had her magic, she had her ambition, and she had intellect. Others just stood in her way or held her down. So what do you do when your plans for world domination fall through?