An alternate end to the Season Four Finale, taking into consideration some details that came to my mind and weaving a short story from them. Also, my first serious (and successful) attempt at a one-shot.

Twilight Sparkle decides to give the villain Tirek all alicorn magic in exchange for her friends. Naturally, this doesn't include Discord. After all, Celestia told her he was a traitor and helped Tirek steal all the magic in Equestria. Discord feels betrayed. Twilight as well. So does Tirek.
Nothing good can come out of this.