Twilight woke up from a strange dream, in which she attacked another Twilight with Dark Magic while dodging floating pies. 'What a weird dream,' She thought.
Still, the reminder of what had been promised the night before excited her, waking her up completely in a matter of moments. Rushing downstairs to her desk as fast as she could without waking Spike, Twilight said, "It's morning! Have you rested enou- Sombra! What happened?"
The night before, she had left Sombra's horn sitting on her desk. Now, in its place was a blood-red crystal, with a black string tied through it like a necklace or pendant.
"Just a little disguise," came Sombra's reply. "After all, you would not want your friends to find out about me, would you? After the kindness you have shown me, I would hate to cause you any hardships."
Twilight was surprised, not expecting that simply sparing his life would spark such gratitude from the ancient king. Meanwhile, Sombra was hoping that she would believe the excuse he had come up with, in order to make sure that word of him being alive did not get back to the Two Sisters or Princess Cadance.
"Well, um, thanks, I guess," Twilight said. However, her excitement quickly returned, and she asked, "So, are you going to teach me some of your magic now?"
"No," Sombra replied shortly.
"WHAT!?" Twilight cried out in annoyance. "But you said-"
"I said that you had talent," Sombra replied sharply. "However, if you cannot harness Dark Magic correctly, it would be pointless for me to teach you anything else. A foal must stand before they can trot, and trot before they can gallop."
"So, you're saying that you'll only teach me your spells once I've learned how to properly use Dark Magic?" Twilight asked. "But I don't even know what I'm doing wrong!"
"Precisely, and thus, that is what we shall work on now," Sombra explained. "First, I want you to touch your horn to the crystal that mine has become."
Twilight hesitated. While she was eager to learn new spells, she had not forgotten who she was dealing with. "What are you planning to do?"
However, Sombra had his response ready. "My disguise will not be of much use if anypony hears me speaking. Thus, I will use some of my remaining magic to create a telepathic link between us. This will also make it require less power for me to communicate with you, and thus easier to teach you."
Given that explanation, Twilight nodded in understanding. "Alright, but remember: try anything funny, and I'm taking you back to Cadance in the Crystal Empire. Got it?"
"But of course," Sombra replied smoothly. His tone turned sad as he added, "I merely wish to pass on my knowledge to a worthy student, before my power runs dry, and I fade from this world forever." Of course, Sombra knew he could sustain himself indefinitely, even regaining his power slowly when resting, but there was no need for her to know that just yet.
Twilight, of course, had no way to know that, and his words swept aside any remaining suspicion she had, for the moment. Leaning down, she touched the tip of her horn to the crystal, as he had requested. A moment later, she felt Dark Magic emanate from Sombra's crystalline form and begin slowly traveling down her horn. It felt familiar, yet different, not hurting at first, but merely feeling strange. When it reached her skull, though, a sharp pain did strike her, like a blade piercing her brain.
After what felt like an eternity, but was likely only a few seconds at most, the pain began to fade, and she heard somepony screaming. A moment after that, she realized it was her own voice she was hearing.
"Twilight! Are you okay? What happened to you?"
Cracking her eyes open, Twilight took stock of her surroundings. She was slumped on the floor in front of her desk, her front hooves pressed against her horn. Standing in front of her was the one who just spoke, her assistant Spike. The baby dragon looked worried, obviously having been woken up by her cry of pain.
"I, uh, tripped and hit my horn on the desk," Twilight said. "Sorry for waking you up."
"Really? You sounded like you were in pretty bad pain there. Does hitting your horn hurt that bad?" Spike asked, not having one himself.
"Y-yeah," Twilight replied, thinking quickly. Noticing how sore her throat was after that scream, and needing to distract him for a moment, she added, "In fact, it's given me quite the hornache. Think you could grab me a glass of water, Spike?"
"Sure thing, Twilight!" Spike said, eager to help, before scampering off to do as asked.
As soon as Spike was out of earshot, Twilight whirled around to face the crystal on her desk, and hissed angrily, "What in the hoof was that!? I told you if you tried anything-"
'There is no need to speak aloud, my dear Twilight. The spell was a success.' Twilight was cut off by Sombra's voice echoing in her head. 'Unfortunately, that was my first opportunity to use that spell since I conceived it, so I was unaware of it having such a painful side-effect.'
Before Twilight could think of a reply, Spike returned with the water she had requested. "Here you go, Twilight!" Spike said happily, glad to have been of assistance. "Are you feeling better?"
Genuinely thirsty, Twilight downed the glass of water and smiled at the baby dragon. "Much. Thanks, Spike."
"It was nothing!" Spike replied proudly. "Just doing what any Number One Assistant would do!"
Twilight wanted to start practicing right away so that she could learn Sombra's spells as soon as possible, but she knew Spike would overreact if he saw it. Suddenly, her eyes widened, as she was struck by an idea. "Say, since you've been such a great assistant lately, why don't you take the day off?"
"Huh? But what about you?" Spike asked. "Weren't you going to be practicing some new spells today?"
"Yeah, but… my horn's still sore, so I'm just going to rest today, instead." Twilight said, although part of her felt a bit guilty about how easily these excuses were starting to become for her. 'Still, I've made up my mind to learn what Sombra has to teach, and it won't harm Spike to be somewhere else while I practice.' Twilight thought.
However, someone heard that thought, and responded. 'Indeed,' Came Sombra's voice in her mind. 'Dark Magic can be volatile before it is mastered. It is clear how much you care for your friends, that you would forgo their aid to see them remain safe.' While the telepathic link did not let him truly read her mind, Twilight had not been as careful to guard her mind as he had, and some of her thoughts had leaked through, making Sombra realize that he needed to speak up to keep her from changing her mind about keeping his continued existence secret.
'That's right! I just want to make sure that I don't accidentally hurt Spike,' Twilight agreed mentally, Sombra's words making it much easier to justify her choice. The telepathic communication had transpired in mere moments, keeping Spike from noticing anything. Out loud, she said, "Why don't you go see what Rarity's doing? You won't miss much here."
Perking up at the mention of the unicorn who held his heart, Spike was eager to agree. "When you put it like that… Are you sure you won't need me today?" Despite his helpful nature making him ask, the young dragon was already moving towards the door.
Twilight just laughed, as she said, "Go on, Spike, have fun! You deserve a day off."
"Well, alright," Spike replied. As he left, he called out over his shoulder, "See you tonight, Twilight!"
As the door closed behind him, Twilight breathed a sigh of relief. 'Well, if you're quite finished wasting time trying to spare your minion's feelings, perhaps we can begin with your training.' Sombra voice sounded in her mind once more, a slight note of impatience coloring his tone.
"Hey! Spike's my friend, not my minion!" Twilight snapped back, forgetting that she did not need to speak aloud. "Besides, you haven't even told me what I did wrong yet."
'Oh, really? I was not aware that "friends" pandered to your every need so eagerly. And you certainly seemed to have no problem taking advantage of that.' Sombra replied snidely. 'Now, start channeling Dark Magic so that I can explain.'
"I do not take advantage of Spike!" Twilight cried out in anger, as her eyes began glowing green and the blackish-purple aura of Dark Magic surrounded her horn. "Now will you shut up about that and tell me how to do this without my horn hurt-!" Twilight stopped mid-sentence, as she realized her horn felt perfectly fine. "My horn doesn't hurt!" Turning to the crystal on her desk, she asked, "What's going on?"
Sombra laughed, before responding, 'Forgive me if my methods of teaching are a bit more direct than whoever taught you in the past. Dark Magic feeds off of powerful emotions, anger being the easiest for a beginner to invoke. Attempting to use it while the mind is calm causes the magic to inflict pain on the caster for it to feed off of, instead.'
As his explanation cleared the anger and confusion from her mind, Twilight felt the pain start to return, confirming his words. "So, you're saying I can only use it when I'm angry?" She asked, her annoyance at that lessening the pain, but not being strong enough to eliminate it entirely.
'No, any sufficiently powerful emotion can feed Dark Magic, but until you discover what works best for you, anger will be easiest for you to harness, especially since you were lucky enough to have me teach you.' Sombra's reply was undeniably smug.
"What do you mean by that?" Twilight asked warily.
Sombra was quiet for a moment, as he weighed the risk of his next words, but decided it was necessary. 'Do you realize how close you came to losing everything in the Crystal Empire?'
"Huh?" Twilight's confusion returned full force. "What do you mean?"
'I mean, if you had been just seconds slower finding the heart, I would have returned,' Sombra's voice hissed in her mind. 'If the Prince there had been just seconds slower reacting to my charge, I would have destroyed the Crystal Heart. If the Princess had been just slightly weaker, I would have caught her, and still claimed the Heart. If any number of things had not gone your way like they did… I would have won. And if I had, then my former slaves, your friends, and you would have all been at my mercy. And as for the Prince and Princess…'
Suddenly, an image filled Twilight's mind. A terrifying image of Princess Cadance and Shining Armor surrounded by dark magic and writhing in agony. Twilight's anger had been growing the longer the ancient tyrant went on, but that image caused her fury to peak. "Don't you dare threaten Cadance or my brother!" Twilight shouted at the crystal on her desk, while firing off the Dark Magic she had built up at it as well.
The blast was larger than she expected from an unfocused spell, completely destroying her desk and the wall behind it. Sombra's crystal, however, remained unscathed, protected by its own aura of Dark Magic. As Twilight stared in shock at the destruction she just caused, she saw several ponies stare at her nervously through the hole, before hurrying on their ways.
'Most impressive,' Sombra spoke up before Twilight could act further. He was surprised to discover that the husband of the new Crystal Princess happened to be his student's brother, but he had more important things to focus on, at that moment. 'There truly is no denying your talent for Magic, Dark or otherwise. Whenever you find yourself struggling with what I have to teach you, remember those words, and that image. Hate me for what I did to the Crystal Ponies, what I would have done to you, those you love, and everypony else. Your Wrath will fuel Dark Magic easily, allowing you to shape it as you wish. Hate me, and your power will only grow.'
Twilight stared at Sombra's crystal in shock, understanding causing her anger to fade, but she knew that it would come back easily with such a memory. "Why?" Twilight whispered. "If you hadn't formed a shield, I could have…"
'Killed me?' Sombra finished in an amused tone. 'If you had succeeded, then I would not have been a very worthy teacher, now would I?' Sombra chuckled, before saying, 'I do need some rest after that, though. You should practice channeling Dark Magic while you clean up, and I shall teach you the first of my spells tomorrow.'
As Sombra fell silent, Twilight did as he suggested, her mind in a maelstrom. Part of her wanted to hate Sombra, even if what he had said was solely to motivate her. Yet, she was glad that she could start learning new magic. She was terrified that he had thrown her off balance so easily. At the same time, however, she could not help but admire how swiftly he had provided her with the means to use his style of magic.
'Conflicted' was an understatement.