Trapped in a future where Twilight--now known as Andromeda--has turned into an uncaring, emotionless dark-magic wielding empress, Rarity sometimes contemplates just... you know... accelerating her trip to the heavens, so to speak.
"An Age of Darkness will come when the lessons of Harmony are forgotten. When Equestria reaches this darkest hour, the Protectors of Equestria will return to lead the way back to Harmony." -- The Final Prophecy of Princess Flurry Heart