I will take your soul with me, Twilight Sparkle.
The words seemed to echo in Twilight’s mind, a thought rather than a voice, something felt rather than heard. All the same, she stopped and looked about the hall of the Crystal Castle, searching for what might have put the thought in her head, but saw nothing out of place, heard nothing save the sounds of her friends further down the hall, laughing and celebrating their victory as they trotted down the hall on their way outside. Nothing remained of the Black King Sombra or his terrible reign.
Yet as Twilight joined her friends, and joined the cheering throngs of crystal ponies awaiting outside, she sensed something was off. Why were those words, the penultimate statement of King Sombra, resonating in her mind? Were they words to be remembered and heeded, or simply the ravings of a doomed villain?
All along her way out of the Crystal Empire and through the arctic on the way to the train station, Shining Armor and Princess Cadence following along, Twilight knew something was wrong. She couldn’t quite put her hoof on it, which confounded her. It was as though she was hearing whispers in her mind, too quiet to make out. As they neared the outpost, the feeling worsened. Twilight wanted to call out to her friends, but they seemed blissfully unaware, still smiling over their victory. What is wrong? She wondered. Is it... just me? Is the dark magic still affecting me? She took a moment to center herself, to purge all the negative thoughts from her mind. It was certainly calming, but the voices persisted.
They boarded the train, Twilight following last. She forced a smile as she waved to Shining Armor and Cadence, before the train gave a sharp whistle and began to move. She glanced up at the beautiful tendrils of light emanating from the Crystal Castle - a symbol of their triumph - and for a moment her smile became real.
Then, the whispers in her mind ceased to be whispers. All this was mine...
Twilight froze in place, her smile changing to a look of horror. She knew that voice – deep, growling, and dark – the voice of King Sombra himself! She opened her mouth to say something, but found she lacked words. What’s going on? Am I going insane? What am I going to tell everypony?
Nothing, the voice replied. You’ll act as though everything’s normal.
What? Twilight was practically freaking out. Why would I do that?!
Because you don’t want everypony thinking you’re insane. You see your friends? See how happy they are? You don’t want to ruin that with your worries, do you?
Twilight grimaced, a gesture her friends fortunately missed, oriented as she was towards the train door. She glanced at her friends further inside the train, all looking at her expectantly. She gave them another small smile before trotting over to their car. She sat apart from the rest, gazing out the window, saying nothing to her friends of the voice inside her head.
What’s going on? She demanded of it. Why are you in my head? Why aren’t you gone?
You know so little of the true power of darkness, foal. Twilight could “sense” a laugh. But have no fear. I’ve no intention of driving you insane. I’m just… going to reside in your mind for a while. I promise I won’t interfere with your studies… in fact, I plan on helping with them.
Twilight scowled. Thankfully, facing away from the others as she was, her friends saw nothing. I’m not interested in learning anything you have to teach me. You’re an evil tyrant who tried to kill my friends and family, and tried to make me into your slave!
Favored servant. the voice replied in a disapproving tone. It’s quite a shame you decided not to stand by me. The deeds you could have accomplished…
Twilight felt a growing sense of anger. I’m not interested in “deeds.” I have my friends, and my mentor, and my values, and that’s all I need!
Hmph. Have it your way, then… for now.
Just then, Spike interrupted Twilight’s thoughts with “Hey Twilight, are you all right?”
She turned to him and her friends with a smile. “I’m great. Just great.” Now shut up, she said to Sombra. I can’t act normal if there’s a second voice in my head.
Twilight received a psychic growl in response – doubtless he wasn’t used to such blatant disrespect – but he did his part and shut up. For now.
“You’re sure, darling?” Rarity piped up. “You’ve been through a lot.”
“I... I will be. I just... I need a little time to myself.” She glanced back outside. The sun was below the horizon, the light of its last rays splashing red over the fields of snow. “I think I’ll turn in early, get some rest. I could certainly use it.” She yawned and began to trot off to the sleeping car, heedless of the looks she could feel on her.
As she settled into a bed, she thought, How did this happen?
All that you need to know is that linking minds with somepony is far more dangerous than you’d predicted.
So, the very spell that had allowed Sombra’s defeat had put her in this situation. It seemed Sombra was always one step ahead. What do you want?
The same as you, to get out of your mind. Except in my version, I have a proper vessel in which to reside. Now... He paused menacingly, and Twilight could just imagine his fanged grin. Sleep, and know that I will be waiting for you when you awake.
Twilight stood atop the balcony of a corrupted Crystal Castle, garbed in a flowing indigo robe and black armor, gazing down upon lines of chained crystal ponies. She grinned with glee as they marched along before she turned back and sauntered inside the onyx castle.
Guards saluted her as she passed, while the common slaves bowed to her. At last she came to a chamber resembling a conference or dining room, where a blue crystal pony stallion was standing, head held low and flanked by two guards.
“You!” Twilight said to the crystal slave. “You… are three minutes early.” The slave perked up and looked at her as she continued. “Proceed to my chambers. I shall assign your next task shortly.”
“Yes, of course, mistress Sparkle!” With that, he cantered off into the halls of the castle, nearly running into an equally-hasty orange mare on her way into the room.
“You!” Twilight barked once again, causing the mare to jolt. “You are 12 seconds late. Your new task will be to serve as practice dummy.” Two of the guards moved to flank the orange mare, who looked absolutely terrified.
“No, please my mistress, I-“
She was cut off by her own scream of pain as Twilight tested her newest spell on her, firing a beam of dark magic at the unfortunate slave. Twilight almost had a similar scream of fright on her lips when she awoke.
Twilight looked about her. Her friends were still asleep, and since the sleeping car had no windows it was difficult to tell what time it was. At last she lay back down to sleep and closed her eyes.
Why did you turn your back on that?
Twilight opened her eyes at Sombra’s question, even though the gesture was meaningless. On what? On hurting other ponies? When will you get it through your head that not every pony is as power-hungry as you are!?
It felt good to you, didn’t it? Don’t deny it. The thrill of having power over others, of exploring the depths of dark magic, take your pick. You enjoyed it.
Only because you messed with my mind!
Sombra laughed. Whatever helps you sleep at night. Not that you’ll have much luck with that, now that I can sense your nightmares…
Twilight gulped, then thought of something which brought a defiant smile to her face. We’ll see about that! As soon as we get to Canterlot, I’ll see Princess Celestia, and when I tell her about you-“
Then you’ll admit to her that you failed.
Twilight’s smile faded. W-what?
Your responsibility was to protect the Crystal Empire, and by proxy, defeat me. Do you really want to admit to your mentor that you failed in your task, that you needed and need help in your test? As I heard from your thoughts, this test is a very important thing for you… enough that you’d do nearly anything to pass.
Not anything! If it means getting rid of you…
And you would do that, how?
Twilight didn’t have an answer. He’s right… a memory spell won’t work, he’s not a part of my memories-
-And simply attempting to excise me from your mind could take a part of you as well.
Twilight jolted. This was the first time he’d reacted to any thought not directed at him. Even in the face of being constantly mind-read, her analytical mind continued to work. He… either he’s been hiding the ability to read all my thoughts, or the connection is deepening.
Precisely, Sombra intruded again. You don’t know how deeply my mind is intertwined with yours, or what I’m capable of. Any attempt to remove me could leave you changed, mentally scared, even insane. And that’s if the effort succeeds. Only Celestia knows what she’ll do to you if it doesn’t work.
If it means getting rid of you once and for all-
And if it doesn’t? If I’m able to rise again from the shattered remnants of your mind? My recommendation to you is to accept the fact that we are going to be together for quite some time… unless you do the proper research.
Twilight paused for a moment, before coming to a revelation. That’s it! I’ll just do research until I figure out a way to expel you from my mind for good.
Would you for like for me to give you a hint?
No! I’ve had enough from you! She turned over in her bed and closed her eyes. Now let me sleep.
She did not sleep well.
She thought about her situation. Should she tell Princess Celestia? In truth, she had no idea what Sombra was capable of. If she did anything wrong, not only would Sombra know about it ahead of time, but there were all sorts of things he could do to her if she even thought about it. She shuddered and he chuckled at the thought.
“It’s beautiful,” Celestia said, gazing out the castle hall windows at the streams of aurora coming from the Crystal Empire.
“I wish it had been me who ultimately made it so,” Twilight replied, head hanging low. “But it wasn’t.”
Really? Sombra said to her. You’re going to downplay your own achievements?
What achievements?
“As I understand it,” Celestia continued, heedless of the inner dialogue Twilight was going through, “You took it upon yourself to distract Sombra while your friends retrieved the Crystal Heart.” She glanced at a nearby stained-glass window, which depicted Twilight and Sombra apparently locked in a battle of wills while her friends snuck away with the Crystal Heart. “You were willing to potentially sacrifice yourself to ensure the safety of your friends and the entire Crystal Empire. In my opinion, that’s the greatest act of friendship I’ve seen from you.”
Twilight’s ears perked up and she looked up at Celestia as the latter approached her. “Far better that I have a student who understands the meaning of self-sacrifice than one who only looks out for her own interests.”
Twilight’s expression was one of mixed anxiousness and wonder. “Does this mean…?”
Celestia smiled for a long moment before answering. “Yes.”
In another moment, an unsuspecting dragon was knocked aside as Twilight flung the door open. “I PASSED!”
Her friends gave assorted cheers and shouts of victory as Spike hugged her as she smiled. Even Sombra seemed impressed. Well handled, Twilight.
Then the singing began. Starting with Rarity: “You were prepared to do your best…”
What?! Sombra said to the only pony who could “hear” him. Tell me you’re not-
We are.
When it was over, Twilight sensed a small thought from Sombra, quiet and directionless, as though he was thinking to himself instead of her.
What was that feeling…?