After a freak accident, Princess Celestia finds herself in a whole new universe. As she seeks a way home, she is captured by none other than Team Rocket.

Welp.

Now on TV Tropes.

This story is a sequel to The Return of the Shadows

Princess Celestia sends King Sombra to Ponyville to learn about friendship with Twilight and her friends.
But days passed, and between Sombra and Twilight something else grows.

This story is a sequel to Lost into Shadow

Twilight has failed, or rather, she has succeeded. Her darkness is her power, and together with her husband, Queen Twilight has a new plan for all of Equis. The black castle rises to greater power than has ever been seen before. War is brewing while alliances are forged and others are broken. The days of harmony are dead and gone, and all the world will be forced to mobilize against the might of the Nightmare Hordes. Will they prevail in the faces of Wrath and Despair? Do they have any hope of someday returning to a time of peace and love?
....
........
Not a chance, because in Chapter 1, Hope dies.

Twilight had reached her peak, she was at the happiest point in her young life. The day of her coronation as Equestria's newest princess had finally arrived. Then the unthinkable happened, Sombra appears in the throne room alive and well demanding his chance to be reformed by pony society. The unthinkable happens again, when his wish is granted, spearheaded by none other than Princess Twilight herself. Will Sombra's nefarious plans bring her to ruin, or will she succeed against all odds? Only time can tell as it reminds them both that plans have a way of changing all on their own.

This story is a sequel to Lost into Shadow

The impossible has happened, through all the pain and darkness, Twilight Sparkle succeeded in her impossible mission...mostly. King Sombra is still plenty rough around the edges, but despite being an old dog he's making an effort to learn new tricks. Where will this new way of life take him? He has absolutely no idea, but with his queen to guide him, what could possibly go wrong?

King Sombra, the tyrant of Crystal Empire is back, only to be imprisoned by princesses and put through reformation with Twilight Sparkle as his teacher. Can somepony with heart as black as night be reformed? Twilight believes so. Sombra in other hoof isn't so sure but something in that mare makes him try.

This is going to be one of my longest stories this far. Marked Teen for sexual innuendo and slightly gory-ish scenes. Nothing too bad though. Also this will not be a story that deserves a dark marking.

For now I'd like to thank Alun Aleriksson, pony of change, Microshazm and Sidetrack for helping with the grammar and overall writing in general. Thank you so much.

Cover art by lorekhearts.

Searching for any records King Sombra may have left behind, Twilight learned of the shadowy king's tragic past. However, she also discovered his horn, in which his mind and remaining power were contained. Determined to learn how to use his Dark Magic for Good, Twilight brought Sombra back to Ponyville with her. After all, what could he possibly do as a horn? ...Or will he stay that way?

Edited by Darth Vendar and Myrkur
Inspired by Issue #1 of FIENDship is Magic
Gore tag just to be safe.

Edit 06/15/23: Now in the top 2K stories on the site, by rating! Thank you all!

This story is a sequel to Shattering a Heart of Darkness

After returning to the side of good and banishing a threat to Equestria, Sombra is dealing with new changes, both physically and emotionally. He is now dating Twilight Sparkle and has moved to Ponyville with hopes of a fresh start. What kind of wacky adventures can the former Shadow King get into?