For some reason, I'm imagining Sombra (yes, I know he was barely a character in canon, just go with it) as Silva. A sacrifice was needed from among Celestia's apprentices, and he drew the proverbial short straw...
and yeah, it probably should considering the fact that [SPOLER ALERT] Skyfall was the name of a place rather than a character. But I find that portmanteaus of names are more memorable for crossover titles, and Twilight was the only one that fit properly (except for Piefall, which was already taken by ).
Heheheh, you can continue it a few scenes ahead. Luna making a psychological test on Twilight, while Celestia watches behind a mirror: Luna: So let’s begin. I say “day”, you say… Twilight: “Wasted” Luna: Country Twilight: Equestria Luna: Fun Twilight: Books Luna: Employment Twilight: Books Luna: Friend Twilight: Books. And Spike Luna: Celestia Twilight: B@#$¨&* Luna: Ponyville Twilight: … Luna: Ponyville Twilight: Done.
Celestia: Regret is not part of our profession. Discord: They kept me for five months in a room with no air. They tortured me, and I protected your secrets. I protected you. But they made me suffer. And suffer. And suffer. Until I realized, it was you who betrayed me. You betrayed me. So, I had only one thing left. My chaos capsule in my back left molar. You remember, right? So, I broke the tooth and bit into the capsule. It... burned all my insides, but I didn't die. Life clung to me like a disease. And then I understood why I had survived. I needed to look in your eyes one last time.