Luna entered Twilight Sparkle’s dream, to find herself in Ponyville. It seemed peaceful but oddly empty. However, that peace was shattered by a massive blast of magic that knocked down a nearby building.
“You’ll have to do better than that!” Roared a deep base voice… a voice Luna recognized, even after 1,000 years.
“King Sombra!” Luna gasped, flying towards to source of the disturbance as swiftly as she could. She found Twilight dodging between buildings, with the ancient tyrant chasing after her. Before Luna could intervene, Sombra launched another magical blast at the unicorn he was chasing.
Only for Twilight to shift into Shadowform, and simply part herself around the attack, before rounding the next corner.
Luna froze in shock for a moment. She had seen ponies dream of having Dark Magic before, although thankfully not many. However, they invariably got some aspect of it wrong, since they did not truly know how such magic worked. However, the magic of both Twilight and Sombra acted exactly as it should, which meant… “Twilight really does know Dark Magic!” Luna said to herself, suddenly growing even more worried than Celestia had been. Her sister might know that it would be bad for Twilight and those around her if she became corrupted by such magic, but Luna knew far better of just how terrible things could become.
Acting swiftly, she charged her magic and chased after the pair.
Cornered in an alley between two buildings, Twilight turned to face her pursuer. Gathering her own dark magic, she cried out, “Don’t think I’m going down without a fight!”
Sombra grinned as he stalked towards her… only to be blasted aside by a third party. As Luna swooped in, she looked to Twilight, and shouted, “This is your dream, Twilight Sparkle! King Sombra is gone, this is only a reflection made by your subconscious!”
Shocked by the princess’ words and sudden appearance, Twilight was unsure how to act at first. However, Sombra’s voice appeared in her mind once more, his previous irritation put aside to deal with the current obstacle, ‘Play along. I would not want you to suffer the Princess’s wrath simply for letting me live. Attack me, and I will leave the dream.’
Acting quickly, Twilight attacked him as he instructed, and when the light from the attack cleared, Sombra was gone without a trace. Twilight sighed in relief, glad that Luna had thought him just part of her dream.
Luna landed next to her with a frown, her eyes locked on the young unicorn. “Twilight, that was Dark Magic you were using,” Luna said firmly, her tone telling Twilight that her words were not a question.
“Uh, um, well,” Twilight stammered nervously. Getting an idea, she said, “Well, King Sombra could do things with his magic nopony else could, so I guess I started dreaming that I could do the same.”
Luna frowned further, before saying, “I have seen the dreams of many who dreamed of having such powers. Dark Magic has a seductive allure that calls to many, although few manage to harness it, fortunately. However, unlike those that merely dream of it, you use such magic as it truly functions, and with the clarity of real knowledge.” Luna’s voice grew gentle, as she said, “There is no need to lie to me, Twilight Sparkle. I know well how hard it is to resist the temptation that comes with such power.”
Twilight lowered her head, properly chastised, but she knew she still could not tell the princess the full truth. “I’m sorry, Princess Luna.” Twilight had read several books on psychology and knew the keys to a convincing lie were consistency and a bit of truth. Of course, she had always thought that she would use that knowledge to spot other’s lies, not help her make one. Out loud, she said, “Cadance called me back to the Crystal Empire to see if Sombra left anything behind. I found a book owned by Sombra that explained how to use Dark Magic, and… well, I thought that it would be a shame to let such knowledge go to waste if I could figure out how to use it for good.”
Placing a hoof on Twilight’s shoulder, Luna replied in an understanding tone. “The preservation of knowledge is a noble pursuit. However, there is nothing good to be gained from Dark Magic or anything else to do with that monster, King Sombra.”
“That’s not true! He-” Twilight blurted out, before cutting herself off. She had been about to say ‘He’s not a monster’, but caught herself. Instead, she said, “I used Dark Magic to rescue my friends from Trixie when she got ahold of the Alicorn Amulet. If not for what I learned, who knows if I would have been able to save then!”
Luna shook her head, replying, “Dark Magic is capable of great things, it is true, but the cost is too terrible for any pony to bear. It feeds off of dark emotions like anger and jealousy, and promotes such feelings to come more easily in the future.”
“But, Sombra sa- er, Sombra’s book said that any emotion could be used, as long as it was powerful enough. Even positive emotions could fuel Dark Magic.” Twilight said.
Luna hesitating at hearing that. “I have heard nothing to support such, nor did my own experiences with Dark Magic leave me ever feeling that that could be possible,” She said, after considering the unicorn’s words.
“But Sombra is a master of Dark Magic.” Twilight continued her argument. “If anyone would know its secrets, it would be him. Besides, if I can learn how to use it without getting angry, we’ll be prepared for if another enemy like Discord shows up, who can stop us from using the Elements of Harmony!”
“Perhaps, but Sombra was also a liar and a manipulator,” Luna said firmly. “If it weren’t for him, Nightmare Moon may never have existed.”
“What?” Twilight went wide eyed in surprise. “What happened?”
Luna pondered for a moment whether she should tell Twilight the tale. ‘I’ve never told anyone, not even Celestia,’ Luna thought, ‘but if it keeps Twilight safe, then so be it.’ With that thought in mind, she began to speak. “When we went to stop King Sombra a millennium ago, the fight was not as one-sided as we would have wished. He knew we were coming, and was prepared. There was a door, a trap. It locked us in living nightmares, forced to watch our worst fears play out. I was able to break free with a powerful pulse of magic, but my sister remained trapped. Before I had a chance to help her, however, King Sombra confronted me. He filled my ears with pretty words, complimented me, flattered me, and told me that only the greatest princess deserved to rule Equestria, that one day Celestia would cast me aside. He played to me ego and preyed upon my worst fears. And worst of all, he showed me what Celestia most feared...
“My own sister’s greatest fear… was me.”
Luna looked off into the distance, as she relived one of the worst days of her life. “My own sister fearing my power. I wanted to believe that it was a lie, but I knew that my magic had grown stronger than hers, and in my pride, I let his whispers get to me. However, Sombra had underestimated me, lowered his guard. And that was when I struck.”
Turning back to Twilight, she finished, “I thought I had broken free of my fears, but I had only gained enough space to rush headlong into my fate. With my hatred awakened, I turned the full extent of my power on Sombra and trapped him in the Frozen North. The seeds of darkness were planted within me, though, and… well, you know well enough what that lead to.”
“I… I’m sorry to hear all that happened to you,” Twilight said, before her resolve firmed, “but I won’t let that happen to me… and neither will my friends. If I were alone like you were, then I can’t say that I wouldn’t have done the same. I know that I’m not alone, though, and with the feelings of friendship I have in my heart, I know that I can find a way to use that power to help protect those I care for.”
Luna just stared at the young mare before her for a moment, weighing her words, before giving her reply. “Perhaps you are right. Perhaps you can do what I could not. You understand the danger better than I did, and with others to support you, then even if the worst happens, you might be saved before it is too late.”
Turning away, Luna prepared to leave the dream. “Twilight, that book you mentioned…” Luna said before she left, “It would best that you treat it with care. You said yourself that it belonged to King Sombra, and my point stands that he’s not to be trusted. I shall trust your judgement, but my sister and I will have no choice but to intervene, should you fall.”
“Thank you for this chance, Princess Luna,” Twilight replied, bowing to the alicorn.
Smiling back at her, Luna said, “After all you’ve done for Equestria, and for me in particular, I would say that you’ve deserved the benefit of the doubt. Heed my warnings, Twilight Sparkle, and farewell.” With that said, she left the unicorn’s dream.
“Well, that brought back memories.”
Twilight turned around to see Sombra stepping out of a nearby shadow. Frowning, she asked, “What the Princess said, about you trying to corrupt her… was it true?”
“Every word,” Sombra replied without hesitation. “She was my enemy, attacking me with a clear desire for my death, in a cowardly two on one fight. Why would I not attempt to do everything in my power to achieve victory?”
Twilight could not really argue with that logic, but was still concerned. “And what about me? How can I trust you after hearing that?”
“My dear Twilight, how is this at all the same?” Sombra answered her with his own question. “Have I tried to turn you away from your friends? Have I tried to convince you to take over Equestria? Have I even asked for any aid in getting my body back? No, all I have asked for is my life, and the opportunity to teach the most gifted unicorn I have ever met.” Grinning, he added, “I believe I am more intelligent than the average pony, and that means learning from my mistakes.” Making sure to shield the thought, he could not help but add mentally, ‘And that means realizing not to get impatient when turning someone to your side.’
Not knowing his true thoughts, Twilight relaxed and said, “Sorry, I guess I’m just on edge. I hate having to lie to everypony…”
“For which I should be the one to apologize,” Sombra said. Stepping forward, he placed a comforting hoof on her shoulder, as he went on, “My past actions and reputation… Such trouble they have brought you. I know it is hardly sufficient recompense, but perhaps I can teach you a new spell tomorrow, in order to apologize.”
“Thank you, Sombra,” Twilight said with a smile. It was not much, as he said, but learning always did make her happy.
As Luna opened her eyes, she was surprised to see Celestia sleeping nearby, not having even returned to her bed, after their previous conversation. Knowing that the sun would need to rise soon, she nudged her snout, and said softly, “It is time to awaken, my sister.”
Celestia stirred slowly, at first, only for her eyes to snap open as she remembered what she had been waiting there for. “What of Twilight?” She asked. “Did you have a chance to speak with her?”
“Be at ease, Sister,” Luna replied with a smile. “You were right about her use of Dark Magic, but all is well.”
“What? Your words contradict themselves!” Celestia protested.
“The knowledge merely came from a book King Sombra had left behind in the Crystal Empire. Twilight only used such magic to save her friends, and they are aware of her practicing it. Twilight is convinced that she can use Dark Magic to protect Equestria, and with her friends to support her, I am confident that she could succeed, and not fall down the same path I did.”
“Are you certain?” Celestia asked, still worried but knowing that Luna had more experience with such magic. “And what about him?” Celestia looked down towards the castle gardens, leaving little doubt about who she meant.
“I am,” Luna replied. “And I doubt this will affect our plans for him too greatly. After all, it is her friend Fluttershy that you said you believe to be key in that, not Twilight herself.”
“Very well, I shall trust your judgement in this.” Celestia agreed. “I just hope that you are correct.”