Heartwarming / Broken Spirit

• Chapter 12 qualifies. After Discord becomes convinced that Fluttershy's meddling in regards to his past has been an attempt to betray him, he ransacks her cottage and scares the Pegasus away. When he learns from Twilight that everything Fluttershy has done has been to help him, he goes off to find her being attacked by basilisks. After a brutal fight that nearly kills Discord, he awakes and reconciles with Fluttershy.
  Fluttershy: I love you
  Discord: I know you do. I…I know you do
• Chapter 15 has too big ones. The first one is Luna finding it in herself to forgive Discord for murdering her parents and finally coming to see him as an older brother once more. The second one is Discord finally reconciling with Twilight for injuring him after about 15 chapters of antagonism on his part.
• The last three chapters qualify are full of these.
  • Chapter 16, gives us Discord and Celestia finally rekindling the relationship they shared as children after a particularly nasty fight.
  • Chapter 17 gives us Discord leaving Fluttershy's cottage to go live with the Princesses, and finally mustering up the ability to tell the Pegasus that he loves her.
  • From the same chapter, there's also the extremely long letter that the Mane six send to Celestia detailing how Discord's presence has changed their lives.
  • The epilogue gives us Celestia introducing Cadence to her "Uncle Discord" along with Discord visiting his adoptive parent's graves and finally putting the past behind him.