The Return of king sombra and his new plan.

As night fell in the Crystal Empire, Candace and Shining Armor turned in for the night. All was peaceful for a while, the only sound a lone cricket chirping. Suddenly, a shadowy figure emerged from the moonlight, stumbling a bit from lack of sleep. The figure seemed to be particularly interested in the Crystal Heart, as seen when said item was cast in its ever-nearing shadow. The figure had come to enact a sinister plan. It suddenly hit the him that perhaps starting where he was at was not the best of ideas. He would need to mess around with the higher-ups first. The confused villain grumbled a bit about not being able to catch a break before flying to his new destination: Canterlot Castle. Now to get past the guards.

The shadowy figure looked high and low in every room and chamber in the castle once he got in. It took every ounce of willpower to stay on task and not join one of the orgies he had accidentally walked in on, but he eventually found Celestia's room. He decided to take the time to put together a little mind control spell. After, a brief flash of light from his eyes, Celestia began to stir. "I AM KING SOM-" the figure began, uncloaking himself, but Celestia wasted no time and blasted the villainous unicorn with her magic. Sombra got back up and began to enact the mind control part of the mind control spell, only to get hit by an even stronger blast of magic. With that, he was to be banished for a thousand years.
"Us villains can never catch a break."

King Sombra had some fuzzy idea of being prepared at the back of his mind, but really just wanted to relax. Being banished is kind of like a vacation if you think about it. Sombra just chilled in his catacombs, drawing pictures and remembering the sound of an innocent foal's screams. At some point, however, it became time to assemble the plans he had for his dramatic return. He would shout his arrival into the air and cast all of the mind control spells he'd ever need. He would get his revenge on Celestia, trapping her in an odious, fittingly evil fog and banishing HER to the Crystal Catacombs. Queen Chrysalis had recommended it at some point. "As long as there aren't any flowers," she said, "the zombie bridesmaids will be okay." Sombra, though confused, decided to take this location into consideration.

But King Sombra had more to his plan for.He would encase her in his black crystal and give her a dark vision of the future. He would make her death seem slow, and revenge would be sweet- sweet, like Celestia, who could've killed him but just banished him instead. Sombra suddenly saw everything through new eyes, and so Celestia did also as Sombra freed her from his vision-inducing glare.

"Princess Celestia," he began, slightly embarrassed. Villains generally stick to their principals, after all."I want to say that I am deeply sorry for everything I did in the past. And I-" Sombra took a deep breath. At the moment, he felt nothing but love and admiration for the graceful alicorn. " Well-I-kinda-sorta-love-you-a-little-so-maybe-let's-get-married."

Princess Celestia was certainly taken aback, but after a few minutes could see where he was coming from. But the princess was fair on both sides of the coin, and so she decreed that Sombra would have to atone before they could even date. Sombra, saddened at the rejection, decided now would be the time to buddy up with Celestia. What a better way to attract her? Soon he was cuddled up next to Celestia in bed, the two almost falling asleep.

The moon made some headway with regards to its destination by the time and Sombra started to feel strange. It had been a millennium since he last felt this sensation of... of... "maaaaares," he mumbled, drooling. By the time he got to the bathroom, he had a name for this strange state of being, with fuzzy memories of castle orgies playing in his brain. He began to masturbate, but in his heat thought that perhaps he could woo Celestia with his powers of seduction. His cock twitched at the thought of mounting Celestia, his greatest love interest. In fact, he decided to skip the seduction and get started, slapping his dick across Celestia's face to wake her up. With a lusty moan, she rose from her slumber. In times of better judgement, she would kick out Sombra immediately, but he caught her in the middle of a wet dream. Celestia hardly had time to catch a breath before she was deepthroating a cock, albeit reluctantly. She thought back to royal duties that needed doing, but Sombra was a king, after all, and he needed doing as well. Celestia gave in and began swirling her tongue around Sombra's endowment. He smiled at the attention and made his movements a little more fervent. Celestia had trouble taking in the whole thing, but she loved every second. Moaning, emphatically, she began to rub Sombra's balls with her front hoof. The face-fucking reached a climax when Sombra let out his load and withdrew. Despite savoring the slightly salty taste, Celestia's pussy was still on fire.
"Done already?" she said, disappointed.

King Sombra smiled. "That was the first time I've cum in a thousand years. You bet there's more." Celestia purred and wiggled her hips invitingly. Sombra responded by taking a sniff of Celestia's snatch before going headfirst into her juicy pussy. He gobbled up every ounce of liquid with his tongue, eliciting a lusty squeal every time his tongue ran over her clit. Soon Celestia assumed the dominant position, riding Sombra's face over and over. Just as she was about to cum, Sombra backed away, leaving Celestia panting.

"What?" she said, looking quizzically at Sombra. He simply smiled and began to get into mounting position. Smiling knowingly, Celestia exposed her dripping pussy a bit more obviously. Sombra mounted her, however, in her ass. Celestia was so deep in lust that she didn't even care at this point. She yipped in time with the anal pounding, struggling to fit Sombra's cock all the way in. With a final squeeze, Celestia milked Sombra's 1,000 year load with her ass. She came at the same time. Sombra stuck his tongue in her ass and pussy gathering up as much liquid as possible. Then, he french-kissed Celestia, transferring their passionate mixture into her mouth. She smiled and swallowed before collapsing on the bed along with her lover. The two fell asleep, intertwined, as the Luna reeled the moon back in.

"Ass, huh? A risky move. You're lucky I like it."

"Hey, didn't wanna risk getting you pregnant."

"There's a number of fool-proof spells for that and you know it. Now, shoo, I need to freshen up for royal duties."
After a quick shower, Celestia rose the sun and got things in order for guests. King Sombra would have to find a temporary house to stay at for the day so as not to alarm anypony. Princess Celestia offered the cottage just outside Canterlot, but as it turned out somepony had moved in in the past month. The Crystal Empire, while Sombra's home, would be too hard to explain to Cadence. The dungeon seemed inviting for a moment, but... the dungeon. It's a dungeon. Now that Sombra was established as an okay pony, that was no place to go.

But Celestia really want to keep King Sombra around until she found some time to break the news to her in a manner that wouldn't cause the heads of everypony to erupt. And so, Sombra was given a nice enough room in the Crystal Catacombs to stay in, complete with a throne. Celestia, having her reservations, still wanted to keep an eye on him. The solution was simple, she could use the crystals to make sure he stayed out of shenanigans.
She walk down to the room that her sexy guest was to be in during the day, though Celestia had taken a liking to Sombra and decided they could just share quarters in the night. Soon, night had fallen and and it was time for yet another night of passionate lovemaking. That's estrus, folks.

Unbeknownst to Celestia however, a little organism was going to grow. A bit of cum splashed through her cervix- perhaps just one sperm- but the changes would soon occur. The dark side of Sombra... Wanted this to happen.