Chapter 1 - Twilight's Questions
Twilight felt herself coming to. The last thing the purple unicorn remembered was that she was about to fall off a cliff thanks to Nightmare Moon's interference. When she yelled out for help, she expected Rainbow Dash at the least to grab her, but she didn't expect to be grabed by magic of some sort before being put to sleep. It was very obvious who grabbed the purple unicorn: Nightmare Moon.
"Ah, you are awake." A female voice said. Twilgiht recognized the voice.
"N-nightmare...moon..." Twilgiht said as she started to get up.
"It seems my sister saw much potential in you. Twilight Sparkle, I believe is what you go by yes? I've done my homework since our first encounter." Nightmare Moon said.
"Sister? I don't understand..." Twilight said.
"Of course you don't realize it do you. Or, would you like a reminder?" Nightmare Moon asked before levitating a book in front of Twilgiht.
Twilight gasped, recognizing the book. "Th-that's the book that told the legend of the two sisters." The purple unicorn said.
"Now your catching on." Nightmare Moon said. "Before I became Nightmare Moon, I was known as Princess Luna. But, as you had read, I had grown jealous of my sister, but not just because of the day and night cycle." She added. "While that was part of it, the full story is that of denial on Celestia's part." The black alicorn stated.
"D-denail? Princess Celestia would never--" Twilight said before Nightmare Moon started using a spell.
"Do not be alarmed, this spell is only to show you my memories." Nightmare Moon said. Twilgiht could see herself watching things play out in third person, as she watched who she assumed to be Princess Luna over time become disliked in favor of Princess Celestia, some ponies even protesting Princess Luna. And throughout it all, no matter what, Princess Celestia would not address her sister's worsening mindset.
"Ho-how could Princess Celestia...do this to her own sister?" Twilight asked. She knew that if Shining Armor ever did this to her, she would be understandably pissed.
"But there is one thing I do have to note Twilight Sparkle. From the memories I see of you, you like seeing the stars at night." Nightmare Moon said.
"I...have an interest in Astronomy in addition to my studies in magic. So sometimes on clear nights, I like looking at the stary night skies." Twilgiht said.
"When I was still in charge of the night, I would sometimes make the stars make special constalations in honor of a pony I felt deserved it. And yet, no one appreciated what I did." Nightmare Moon said.
"Why are you telling me all this?" Twilight asked.
"Tell me, Twilgiht Sparkle, when you realized my return, and you took your concerns to my sister, how exactly did she describe my return?" Nightmare Moon asked.
"...She treated it...like a myth." Twilight said.
"I was afraid you'd say that. It means even after a thousand years, she has not learnt to understand other's suffering." Nightmare Moon said.
"I...actually feel sorry for you now...Princess Luna. Err...you don't mind if..." Twilgiht said.
"No. Not while we are alone." Nightmare Moon said. "I can tell you understand. You have an older brother in your life. And you don't want what happened with me and Celestia to happen to you and him." She added.
Twilgiht went to Nightmare Moon, and rubbed her head against the alicorn. "I guess books can't teach everything about history." Twilgiht noted.
"Trust me, my sister most likely went to great lengths to purge most of my old self from various books and made sure the public didn't have the full story on purpose." Nightmare Moon said. "But the main reason I wanted to speak with you personally, is because I understand my sister's reasoning behind you specifically. For a unicorn like you, the amount of magic you have is far greater than any Unicorn who came before you or any unicorn who will come after you. In fact, I daresay you outclass even me with how much magic you truely have inside you." She explained.
Twilight's eyes went wide. "You...you mean I have more magic then even you?! But...that would mean I have powers that exceed Princess Celestia herself." She added.
"Indeed you do. But right now, you can't handle all that power. Yes, I think my sister's goal was for you to grow away from her, until doing something that would've unlocked your full magical potential by triggering events that would've no doubt made you an Alicorn Princess." Nightmare Moon said.
"And by that point...I wouldn't even think of turning on Princess Celestia..." Twilight noted.
"But if you wish, Twilight Sparkle, I can help you unlock this potential of yours much better then my sister would've ever allowed. I can help you become stronger then you ever have before. But don't worry about the ones that came into the forest with you. I plan on making sure they join you if that is what you wish." Nightmare Moon said.
Twilight thought about it. Even though those mares were complete strangers to her, whose to say they couldn't become real friends one day? Perhaps now was the perfect time to make them while also going beyond any book she could ever read. After all, Nightmare Moon said she had more magical power then even Starswirl the Bearded; her true idol. If she had more power then he could ever have documented, then why bother with learning magic from books anymore?
Her mind made up, Twilight stood up. "I accept your offer Nightmare Moon. And the others could also join your side so long as they remain the same as they are now." The purple unicorn said.
"A wise choice, and don't worry, I promise you that I will not change the personalities of the mares who came into the woods with you. You have my word." Nightmare Moon said. With a bit of magic, the dark alicorn gifted Twilight with the ability to see in the dark. "Consider this a gift from me to you, it will allow you to enjoy the night sky forever and for always." Nightmare Moon said.
"I will treasure this gift. So, shall we get started?" Twilight asked.
"Not yet. First, those potential friends of yours need attending to. And there's one who I want to personally bring in first." Nightmare Moon said before vanishing in her cloud of magic.
"...I think I know exactly which one she's going for first." Twilight said. She then grinned. "I can't wait for her to join me and Princess Luna AKA Queen Nightmare Moon." The unicorn said.
Chapter 2 - Rainbow's Loyalty
Rainbow had flown over past the bridge, but was quickly subdued by Nightmare Moon's powers.
"Grk...let me go!" Rainbow Dash said. "I won't let you stop me from helping my friends!" She exclaimed. Suddenly, Twilight came into her view. "T-twilight?!" The pegasus said in confusion.
"Just a magical projection. I've learnt quite a lot about Nightmare Moon, formally known as Princess Luna. I've learnt about why Princess Luna had become Nightmare Moon. Her own sister, my mentor Princess Celestia had the nerve to ignore Princess Luna's troubles and woes. Does that sound like real loyalty to you, Rainbow Dash? Is that the sort of Princess you want to support?" Twilgiht asked.
"You...this is one of Nightmare Moon's tricks isn't it? We've encountered a few of them on the way here. How do I know this isn't another one of her illusions?" Rainbow Dash asked. Suddenly she felt something start fucking her pussy. "Ah-aaaaaah!" She exclaimed.
"Because if she was making an illusion of me, she wouldn't be convincing you right now. Just think on what I've told you would you? I'd rather us not end up on opposing sides." Twilight noted before her projection faded.
"Ngh...you think this will effect me, Nightmare Moon?" Rainbow Dash asked. Part of Nightmare Moon's magic took the head of Nightmare Moon.
"I've learnt a few things about you Rainbow Dash. You wish to join the Wonderbolts, isn't that right? How pitiful. Your too good for them." Nightmare Moon said.
"Wh-what are you talking about?" Rainbow Dash asked.
"I did some digging into the Wonderbolts. Seems most ponies who get into them have a political reason to added. And you? Right now your nothing but a nopony to them. Sure, maybe you could amount to something eventually, but how long will it take before they notice your talents? Your very skill?" Nightmare Moon asked. "I can offer you something better. Once I've fully taken over all of equestria, I plan on making my own squadron known as The Shadowbolts. You can become their captain, should you choose to join my side. And trust me, you will be joining my side once I'm done with you." She said.
"N-no...my friends..." Rainbow Dash said as the magic continued to work her.
"Oh don't worry too much about your friends. I made a promise to Twilight that I would be making sure you all join me without changing anything about you or your personalities. She sees you all as her friends see. You don't want to disappoint her, do you?" Nightmare Moon asked.
"S-stop...I c-can't...I w-won't..." Rainbow Dash said as she began to lose herself.
"Think of it Rainbow Dash, your own squadron of super talented stunt fliers that will work to inspire others. After all, isn't that why you want to join the Wonderbolts, to inspire other Pegasi? All of it can be yours. I'll even promise you, your other friends will also join you with their core personalities intact. I promise you that." Nightmare Moon said.
At that, Rainbow Dash's resistance fell. "Yes my queen...thank you..." Rainbow Dash said as she came.
"Good girl~" Nightmare Moon said.
Twilight waited patiently, only for Nightmare Moon to return with a passed out Rainbow Dash.
"Is she alright?" Twilight asked.
"She's fine; the sexual stimuli I provided her was a bit much for her though, it seems. She'll be out of it for a while." Nightmare Moon said. "As such, her mind my be a bit muddled. Just reassure her of the things I told her, and she should be fine. When she's ready..." The black alicorn said. Twilight nodded and used her magic to bring forth a special uniform.
"Of course Nightmare Moon." Twilight said.
"Now then, I must make preperations for the one known as Pinkie Pie. I will leave you with your friend." Nightmare Moon said before leaving. When she left, Rainbow Dash awoke.
"Ugh...that was...so awesome..." Rainbow Dash said. "Twilight? Is that really you this time in the flesh?" She asked.
"Yep. And I wasn't lying earlier." Twilight said. "And neither was Nightmare Moon." She added.
"Your eyes look a bit different. They have this wierd blue glow in them." Rainbow Dash said.
"Nightmare Moon said she casted a spell on me to allow me to see in the dark. After all, how else will I see while everything is nighttime?" Twilight asked.
"About that...gotta know how ponies expect to live with eternal night." Rainbow Dash said.
"Yeah I did some note taking." Twilight said before getting out some notes. "According to what I've discovered, the sun hasn't simply vanished, the moon is just constantly in front of it now. As such, there's still plenty of UV light coming through, enough for crops to be growing." She explained.
"Okay yeah, it is you one hundred percent. That clenched it. If your entire free will was suppressed by Nightmare Moon, no way you'd act like this." Rainbow Dash said. "Guess that means she was telling the truth then after all. As were you." She added.
"But of course we were. What did you expect? Nightmare Moon simply set tests in place for the other girls to make sure they were the right elements. And as for you, she had things prepared to have you know that loyalty to a princess whose willing to ignore her own sister's wishes isn't a princess you should be backing." Twilight stated.
"Heh...guess you bet on the wrong princess then huh?" Rainbow Dash asked.
"Had I known what I know now, I would've defiantly rebeled against Princess Celestia. In fact, she means nothing to me now. Nightmare Moon has agreed to help me unlike my full potential, and I couldn't be happier for it." Twilight said.
"So...Shadowbolt huh?" Rainbow Dash said, noticing the uniform.
"All yours, should you decide to be loyal to Nightmare Moon." Twilight said.
"That's Queen Nightmare Moon, but I suppose as the queen's understudy..." Rainbow Dash said, as she put on the flight suit. "I can forgive you making the occasional slip. After all, I'm the future captain of the Shadowbolts. I'm gonna inspire a lot of pegasi once things settle. Plus...I'm hoping Nightmare Moon can help me with something personal." Rainbow Dash said as she finished putting on the new flightsuit along with the goggles. The cyan pegasus then struck a pose.

Author's Note
The sex scene in this chapter was inspired by this picture: HypnoHub - caption darknessrising (manipper) femdom femsub htpot kaa eyes kinkypinkie manip mind break my little pony nightmare moon rainbow dash resisting sex spiral eyes symbol in eyes tentacle sex tentacles text yuri | 46283
If you want a story that has a similar scene to this one, check out "The Moon's Cold Embrace" by user RunningThrougTheAshes which you can read here: The Moon's Cold Embrace - Fimfiction