Twylight Sparkle: Let her go.
Midnight Sparkle: Why worry about her? Worry about yourself. It’s which you do best.
Twylight Sparkle: For Celestia’s sake, it’s my twin.
It rock if this happen. Similar to the talk between Stark/Iron Man and Stane/Iron Monger on the final boss level of the PlayStation game based on the Iron Man movie.
ItIn my headcannon, Midnight Sparkle returns because of Equestrian Twylight’s sins spilling dark magic. And she kidnaps Sci-Twi to use as cheese to lure Sunset to her, exploiting her compassion. But Sunset proves compassion is a strength instead of weakness.
Midnight Sparkle: Why worry about her? Worry about yourself. It’s which you do best.
Twylight Sparkle: For Celestia’s sake, it’s my twin.