Lightning Dust is a member of the Wonderbolts, and a flying ace if ever there was one. She's also an insufferable jerk, but she's a jerk who plays by the rules that Rainbow Dash laid down when she became Captain of the Wonderbolts, so it's the good kind of jerk. Or at least, that's how it seemed.
In a shocking twist, after years of buildup, she made her move and officially ousted Dash from the Wonderbolts, taking the top spot of the legendary team for herself! Now captain of Equestria's elite fliers, she'd do anything to keep her position.