This is how The role swap goes in Diamond Tiara's Bully Experience.
[The next day, Diamond Tiara wakes up]
Diamond Tiara: [yawns]
[She gets out of bed]
Diamond Tiara: Good morning, Ponyville!
[Lightning Speed appears in the doorway]
Lightning Speed: Morning! [smirks] Blank Flank.
Diamond Tiara: What?!
[She looks at her flank to see her Cutie Mark has vanished]
Diamond Tiara: What did you do with my Cutie Mark?
Lightning Speed: I put a spell on you and those former Blank Flanks so you could have a taste of your own medicine.
[The Cutie Mark Crusaders enter, all bearing cutie marks]