Unsettling dreams are starting to worry Princess Luna. She is positive these dreams hold an ominous portent for all of Equestria, but there is only one stallion who knows for certain the answers she seeks. King Sombra has been imprisoned again in Shadow since his defeat and the shattering of his body, but he is no less cunning and ruthless. And as Luna tries to interrogate him over time, she finds there is a softer side to the unicorn king, one nopony has seen before. But Celestia fears for her younger sister, warning Luna against Sombra's advances. Is the once-tyrant truly starting to court Princess Luna...or is she simply being used as a pawn in his plans to regain power?
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Cover art by the amazing MickeyMonster, who has permitted me use of it for this fanfiction, as this image inspired me to write this story in the first place.
Edited and proofread by my girls TheOneBehindYou and LabyrinthineMind.

8tracks playlist: https://8tracks.com/yoru-the-rogue/lingering-shadows

Twilight, my Faithful Student, my friend, if there is anypony that can create a world of Harmony, true Harmony, it is you.

More than a thousand years ago, my sister and I sought to create a perfect world, a world ruled by Harmony. A world free of evil. We were powerful and believed ourselves above the laws that governed this world. But this world is governed by the laws of Magic, and Magic, it seems, demands balance.

Where there is Light, there is Darkness.
Where there is Order, there is Chaos.
For there to be Love, there must be Hate.
For every Dream, there is a Nightmare.
Each begets the other.

And like boiling water over a fire, each can extinguish the other.

I should not have been surprised when the day came that the evil I had to fight was my own sister. It was the world restoring the balance we so foalishly ignored.

Perhaps, it is for this balance that I now stay my hoof. I have chosen to have you,Twilight Sparkle, act in my stead as the evils I thought vanquished, inevitably return to Equestria. It is in hopes that you may learn this balance, that you may learn from my mistakes. It is not something I alone can teach you, when I myself still understand so little. It is why I must now rely on the help of an old nemesis.

He intends to take you away, my protégé, and make you his own. You must not succumb to his influence. Yet if you are to learn the balance that is at the essences of all things, it will be through him. For the future of Equestria and for the sake of Friendship, you must prevail.

I hope that some day you can forgive me.

Deep under the resplendent city of Canterlot lies a web of vaults, containing many secrets hidden from the common folk. One of such undercrofts shelters an extraordinary artifact – the crimson horn of King Sombra, the uneasy spirit of the corrupted unicorn still within it.

After months of careful consideration, Princess Celestia ventures down into the delves underneath to confront the fallen king, determined to aid him and bring him serenity at long last.

In a feat of jealous rage, King Sombra kidnapped Princess Skyla from her crystal cradle, and took her to a faraway land. She was supposed to be his twisted legacy, his way to reclaim the Crystal Empire, a mere tool to exact his vengeance on the Crystal Princess. She was never meant to become his daughter.

For over a thousand years the crystal ponies have been frozen in time by the curse of shadows, how lucky they are. While the crystal ponies are in deep slumber, King Sombra’s thoughts are restless.

Inspiration

The Crystal Empire was saved. Sombra was cast away via the Crystal Heart's bright light. The battle had been won, however, there were some unfinished business between the King and the Princess of the Night. She wished to see him. Speak to him one last time. She wanted to finally let go and speak what was in her heart. Though perhaps, it was already too late.

His defeat during the siege of the Crystal Empire did not kill Sombra. He was already dying. Now alone in a frozen wasteland, his final moments approach.

Now with audio reading (for older version) by Coombs & Kuroba.