"By Tartarus, what just happened?" Sombra groaned. "I seemed to have stabilized my magic by restoring my body, but what cau-"
However, he was cut off as magic gripped his body, lifting him up and slamming him against the wall, and pinned him there. A moment later, Twilight was in his face, her expression furious, and eyes blazing with Dark Magic. "You tricked me!" She shouted at him, a note of betrayal in her tone. "Everything you said about being weakened and wanting to teach me… those were all lies, weren't they!?"
"It seems I let you rely on anger too much." Sombra grimaced. Focusing himself, he said, "Ask yourself this, Twilight Sparkle; why am I currently trapped here?"
"Because I'm not about to let you get away with anything else!" Twilight snapped back.
"Calm yourself, and listen to what I am actually saying, instead of what you merely think I mean." Sombra's stern, commanding tone cut through the haze of fury around the young unicorn's mind. "I did not ask why you are holding me, but rather why I have done nothing about it."
Twilight hesitated as she considered that. "Because… wait… You should be able to escape or break free…" Taking a closer look at the ancient king, she noticed something she had missed before. Gasping and releasing her magic in surprise, Twilight asked, "Your eyes… your horn! What's going on?"
Indeed, his appearance had changed from what Twilight remembered. His horn, once a sinister crimson curve, was now a normal unicorn's spiral, the same grey as the rest of his coat. Gone was the Dark Magic corruption from his eyes, the sclera a normal white, and the irises were like brilliant emeralds.
"My magic is gone, or nearly so," Sombra replied, as he got back to his feet, "and I feel like I just lived through another Crystal Faire. Knowing what you do of me, my dear student, do you honestly believe that I would willing put myself in such a position?"
"No, you wouldn't…" Twilight hung her head in shame at her overreaction, her eyes changing back to normal as the last traces of her anger and Dark Magic faded away. "When I thought that you'd tricked me, that you didn't really mean what you said about wanting to teach me, I just got so mad…"
"A result of relying on Wrath to fuel your Dark Magic," Sombra explained, his even tone showing that he did not blame her. "I thought we had more time before it would be an issue, but it seems that being ill-suited to relying on anger is something we have in common." Sombra hesitated, as a thought occurred to him, 'In fact, she may be capable powering her magic the same way I do… with the right push, of course. However, I need time to think, to make sure I do not err yet again.' Out loud, he said, "Have no worries, my dear student, we shall find a way for you to properly use your magic without losing control. Now is not the time, however. I need rest after my emergency transformation, and I believe you have a dinner party with the being I suspect was responsible for my unexpected loss of control."
"Discord!" Twilight gasped, as she pressed a hoof to her face. "I had completely forgotten about him! But…" Twilight shot a conflicted glance at Sombra. She knew she needed to deal with Discord first, and while her opinion of Sombra had certainly improved, part of her was still understandably reluctant to completely trust him on his own.
"Twilight," Sombra said softly, her expression giving away her thoughts. "When you delivered me from the Crystal Empire, you very likely saved my life. Even if I had remained hidden, there was a very significant chance that the next Crystal Faire would have been the end of me. As so, I say this with total veracity…"
Twilight's jaw dropped as the proud stallion bowed before her.
"I will see my debt to you repaid, Twilight Sparkle. You need not fear betrayal from me, as I have meant every word of praise I have said to you. If I must be beholden to another, I am glad it is to such a worthy being." With his head lowered, Twilight could not see the grin that spread across his face as he spoke. Stealing away Celestia's prized student. Convincing one of the most powerful ponies alive to trust him. Gaining an ally he truly believed to be worthy of standing beside him. There was so much to make him smile, that it took every iota of Sombra's willpower to keep from bursting into self-indulgent laughter.
"I… I don't know what to say…" Twilight said in embarrassment. Feeling guilty about doubting him, she decided that if she were to truly trust him, she would have to give him a chance to prove himself. "Alright, I'm going to go help my friends deal with Discord. Don't leave the library until I get back, understand?"
"As you wish," Sombra replied, remaining bowing until Twilight left. As the door shut behind her, he stood up straight, his grin splitting his face.
Thinking of all he had managed to learn about his student since he had arrived in Ponyville, he mused aloud. "A noble Canterlot-born unicorn. Student of two powerful rulers. Sister to the former Captain of the Royal Guard turned Prince and sister-in-law to a Princess. Bearer of the key Element of Harmony, Friendship, with a Talent for Magic, itself. I am a fool for not realizing it sooner. You and I share something very important, Twilight Sparkle. We are both superior to the ponies around us, you just have yet to admit it. But when you do… your Dark Magic's power will rival even my own!"
Twilight felt exhausted as she returned to the library that night. Although it seemed that Fluttershy had succeeded in becoming Discord's friend, it had almost resulted in the loss of all of Sweet Apple Acres. "I'm just glad that tomorrow morning Princess Celestia will be coming to get him, and this will all be over," She grumbled.
"Tell me about it," Spike agreed from where he rode on her back. "If I never see another bad guy again, it'll be too soon."
Twilight opened her mouth to agree as they reached the library, only to freeze as she remembered who was waiting for her inside. "Uh, could I get you to wait here for a moment, Spike?" Twilight asked, only to buck him off and slip inside before he could respond.
Slamming the door behind her, Twilight looked around for Sombra. However, he was nowhere in sight. What was, however, was the neatest library she had seen in a while. Hearing muttering from upstairs, she headed towards it. In the bedroom, she saw Sombra going around tidying up the room, repeating something over and over like a mantra of some kind.
"Harmony is a lie, there is only Conflict,
Through Conflict, I become Stronger,
As I become Stronger, my Magic grows,
As my Magic grows, my Enemies fall.
When no Enemy rises to oppose me,
Only then shall I know true Freedom."
"What are you doing?" Twilight asked as he finished the repetition.
Sombra jumped at her voice, dropping a book as he whirled to face her. Releasing a breath as he saw who it was, he muttered, "It seems my ability to sense the magic of others has diminished along with my own power." Composing himself, he answered her question, "What I was reciting was the Umbral Code, the philosophy by which all the Umbrum lived, before being trapped beneath the Crystal Empire. I discovered it whilst learning all I could about my people after I rose to power. I find that it helps me find focus and center my thoughts, as well as acting as a reminder to always strive to better oneself, so as to be best prepared for the next inevitable struggle."
"I was actually curious why you were cleaning up, too," Twilight asked, not expecting such humble behavior from one who had been a King. "Wait, you said all the Umbrum lived by that? Surely a few thought differently."
"Nay, that ideology was central to being an Umbrum, although I was the sole exception. That is a tale for another time, however." Sombra replied. "As for me cleaning, I simply prefer an organized environ over one filled with clutter, although I admit it was much easier to maintain such with slaves at my beck and call. However, lacking such aid, I took it upon myself to clean up a bit. I initially planned to do some reading, but would not have been able to concentrate on the material properly, whilst surrounded by unorganized books lying about, and such."
While he said a lot, Twilight's mind caught on one thing in particular. "What were you going to read?" She asked, curious about what someone like Sombra would have been interested in.
"Well, while I might disdain Starswirl the Bearded for limiting himself in being the Court Wizard for the Two Sisters, even I cannot deny his brilliance when it came to spell creation and magical theory," Sombra replied. "However, many of his texts came out after I was sealed away, and reading through magic is just not the same as having a tome in your own hooves."
"I know, right!?" Twilight said happily, glad to have somepony else to talk to about works that many ponies had never heard of. "My favorite is his 'Advanced Theory of Telekinesis'. What's yours?"
"Of what I have read, I certainly enjoyed 'Experiments in Transformative Magiks' the most," Sombra said, perfectly happy to engage in a scholarly discussion with somepony who actually knew what they were talking about. "I may never have learned the full intricacies of the Shadowform spell if not for-"
Unfortunately, they were interrupted. "Twilight, is everything alright?" Spike called from downstairs.
Both the unicorns froze for a moment before Twilight started panicking. "We were so busy with Discord, I totally forgot about what to say if anyone found out about you!"
"Perhaps I can solve this myself, then," Sombra said with a grin. Moving to the window, he pushed it opened, placing a foreleg on the sill before looking back to Twilight. His expression serious, he spoke with a tone to match. "I have kept nothing from you, my dear student, and I am at the weakest I have been since I was a foal. Will you trust me for one night?"
Twilight stared into his emerald eyes for a moment, wrought with indecision. History said that he could not be trusted, and yet he had done nothing to betray her trust since she had found him as a horn. Suddenly, a thought struck her. 'Maybe he's the same as Discord. Maybe all he needs is a friend, and as Fluttershy said, that means giving him the benefit of the doubt.' Firming her resolve, she gave him a nod.
Flashing a roguish grin, Sombra leapt through the window, his voice trailing behind him. "I assure you, my dear Twilight, you shall not regret this."
Hoping she had not just made a grave mistake, Twilight went downstairs to deal with Spike. And yet, it was Sombra's parting grin that occupied her thoughts through the night.
The next morning, Twilight gathered with her friends and Discord to greet Princess Celestia. Approaching Celestia, Discord bowed and said, "Yes, Princess, I'm ready to use my magic for good, instead of evil." Glancing towards Twilight as he thought about what he had set in motion, he grinned and muttered to himself, "Starting now."
Twilight was distracted, however, wondering where Sombra was, what he had planned, and whether or not her decision to trust him was about to come around to bite her in the tail. She was brought back into the conversation, however, as Celestia leaned in close to her, and whispered, "I'll leave the Elements of Harmony with you, Twilight, just in case."
Focusing back on the situation at hand, she said, "You were right about Fluttershy being the one to find a way to reform Discord. By treating Discord as a friend, she got him to realize that Friendship was actually important to him, and something that once he had, he didn't want to lose." Twilight's thoughts drifted back to the missing Umbrum as she added, "A lesson that could likely help any being change for the better."
Giggling, Fluttershy put a hoof on Discord's arm, and said, "He's a real sweetie once you get to know him."
Most of those present looked away with doubtful expressions. Twilight, however, had to stifle a laugh as she imagined how they would react if she said something like that about Sombra. 'Okay', she thought, 'so maybe he and Discord aren't quite the same case.'
Turning to Discord, Celestia said, "Why don't you go on ahead? I need to have a word with my student, but will follow behind shortly."
"If you insist," Discord replied, before teleporting away.
"Well, Ah know Ah've got plenty ta do back at the farm," Applejack said. Gesturing to the others to follow her, she added, "We'll give ya some time ta catch up."
"Before that, might I have a moment of your time, your highness?"
The deep voice drew the attention of the gathering to a figure in a grey cloak approaching from the Everfree Forest. While the others looked on curiously, Twilight recognized Sombra's voice immediately, a sense of dread building as he trotted straight towards Celestia.
As he drew closer, the Princess smiled kindly, and asked, "What can I help you with, sir?"
"If you would do me the honor, I would have you act as a royal witness for what I am about to say," the cloaked pony replied, "as my words will hold great importance to both myself and another."
"I see," Celestia said, her long rule leading her to truly understand the gravity behind such a request. "Please, proceed."
Turning to Twilight, he said, "Twilight Sparkle. During your recent trip to the Crystal Empire, you saved my life. From what I saw there, and here in Ponyville as well, such an act was no fluke, but a true indication of your noble character. As such, this is no crude life debt, but rather a true desire to follow a pony such as yourself."
Twilight's dread had turned to confusion and was swiftly replaced with shock, as he threw back his hood to reveal his unusual coloring, and knelt before her. Sombra lowered his head and said. "Therefore, I, Black Knight, hereby swear my fealty to you, Lady Twilight Sparkle, until such time as you see fit to dismiss me from your side, or I give my life in your service."