Tear Jerker / Princess Trixie Sparkle

• "We Will Find A Way", which begins with the mane five and Spike feeling guilty about getting Twilight captured.
  Applejack: We've been actin' careless...now our friend is gone...
  • Trixie making it clear she intends to hold Twilight prisoner for the rest of her life, as the latter begs her to change her mind. As seen here
• Twilight finally letting all her emotions out over what Trixie did and her current predicament, while alone with her brother and sister-in-law, as Cadence tries desperately to calm her down.
• Luna's reaction to learning that Celestia has been keeping their third sister a secret from her and their relationship starting to fall apart, after it was finale fixed, as shown in this song.
  • The reveal that Celestia has two sisters who became evil in itself, makes her Dark and Troubled Past twice as worse.
  • Though it is a good thing for everypony else, Luna refusing Astel's offer, after the latter showed genuine happiness at being reunited with the little sister she never knew must have been heartbreaking.
  Shadow: I know Luna, maybe if she'll listen to me..
  Astelle: Enough Shadow, Luna has made her choice. Any semblance of familiar love in me died centuries ago and I was a fool for believing otherwise. She is nothing more to me than another blind subject of Celestia!