Kiss of the Dark is a story written by Soothing Stone. It is a dark and romance story revolving around Twilight Sparkle and King Sombra.
The story is told from the first person POV of Twilight, Sombra and Celestia, changing at certain breaks in the writing.
The story begins with Celestia traveling to the Crystal Empire and comes upon the horn of the late King Sombra, she speaks to the horn as if she is actually talking to its owner, she recounts the events as of late and clarifies that there was no hope for him, she then leaves to host Twilight's coronation.
The horn however hears every word and Sombra rises from the ground with the intent of revenge, he then travels to Canterlot and witnesses Twilight's ascension, seeing this as a change in plans he travels back to the frozen north and creates a castle out of thin air along with artificial dark guards. He formulates a master plan to get Twilight to join his side and overthrow Celestia then pulls out a book on dark magic by Star Swirl the Bearded.
The scene then shifts to Ponyville with Twilight ready to make adjustments despite her new wings, she then receives an invitation from a pony by the name of Forest Mist. She travels to Wispy Woods and meets the pony who introduces himself and gives Twilight a book on dark magic by Star Swirl before leaving, back at home Twilight begins to try out dark magic, Sombra who used Forest Mist as a mere illusion to give Twilight the book watches from his castle.
Later Twilight and Forest Mist meet again and discuss what she learned from the book and Twilight invites him to join her for lunch with Cadance at the Crystal Empire, seeing this as a chance to get back into the empire Mist accepts. At the end of the meeting Sombra reveals that his plans are coming into place while in the process he developed a taste for coffee.