Twilight Sparkle gets into a conversation with Discord, which leads into Discord explaining the formation of the current universe, his own existence, as well as Twilight's new 'true' responsibilities. But some of these things she finds she didn't want to know.

*update* Twilight, finding herself the Spirit of Magic, decides to investigate and get to know the other Spirits, from Triumph, the weakened Spirit of Victory and War, to Harmony, the triplet Spirits of Friendship, to Windigo, the cold spirit of hatred. She also finds herself in a position where she knows more about the universe than Celestia or Luna, and has to decide whether or not to share Discord's knowledge with her mentor and her sister.
The wonderful image of Twilicorn and Discord is by Greivousfan on Deviantart. (not by me)