When Celestia sent Twilight to Ponyville, she sent her there knowing that if all went well, then Nightmare Moon would be defeated. It didn't go well. Nightmare Moon was successful in her take-over of Equestria and the world, plunging land everywhere into a blissful eternal night, with Celestia being banished to the moon to boot. After years of ruling however, Nightmare Moon has to produce an heir to the throne.
They had failed. Nightmare Moon had succeeded in her conquest of Equestria, no matter what Twilight and her new friends did Nightmare Moon was always one step ahead of them, she had destroyed the elements of harmony, the tree of harmony, there was no other power source left to defeat her and because the spark in Twilight was never realized, she and her would-be friends drifted apart and the power to defeat Nightmare Moon was never released.
Soon after that, Celestia was banished to the moon and Equestria became a land of eternal night, several ponies including those who embodied the elements of harmony were now in Nightmare Moons employ following her self appointed rise to being the one and only ruling princess of Equestria, all of them except one. Magic was the most powerful and elusive element of harmony, Nightmare Moon couldn't afford to take any chances and allow herself to be dethroned, especially by a pony so determined as Twilight Sparkle, so Twilight was locked away deep in the caves beneath the Everfree Forest with minimal food and water supplies to ensure her survival and prolonged torment with chains designed to negate the wearers attempts of using magic just for good measure.
However, Nightmare Moon knew she could not rule forever, despite not aging eventually the tire and stress of being Princess would wear her out and could potentially lead to some sort of coup, especially if the same thing that had allowed her to free herself from the moon also happened to Celestia. There was only one thing for it, she needed an heir, but who could be worthy of such a gift as to take part in producing the next ruler of Equestria? Who could ensure that her bloodline would continue and maintain her perfect world? Who could it be that would give half of their genetic make-up to the future ruler and ensure that they would be powerful enough so that even upon Celestia's return they would continue to reign supreme over a land of eternal night?
Nightmare Moon ordered her army to scour the planet and declared that every single town, city and village was required to provide the most powerful male in their respective location to be presented before their princess for inspection in regards to being the most suitable mate. Ponyville's choice was up first, a young pegasus by the name of Thunderlane, Nightmare Moon stared him down and said "Tell me young stallion, what do you think qualifies you to dirty my inner chambers with your vile testicular filth?"
Thunderlane gulped and said "Uh... well, the mares in Ponyville selected me because I'm the most v-virile stallion, your majesty"
Nightmare Moon was thoroughly unimpressed "That is the only basis on which they deemed you to be suitable to lay in my embrace? Pathetic! Take him away, he is of no use to me".
Next was Double Diamond, Nightmare Moon already knew of the town from which he hailed and immediately said "No no no! This male is from the town where nobody is good at anything! Get him out of my sight!"
All manner of males from all over Equestria was presented before Nightmare Moon and none of them were at all worthy of continuing her bloodline, Gladmane from Las Pegasus, a random kirin from the kirin village, a changeling named Pharynx, a random crystal pony, stallion after stallion after stallion from every corner of Equestria and none of them even came remotely close to what she was looking for. The one to continue the eternal night had to be a stallion who was almost as powerful as she was to ensure that her offspring would grow to be just as mighty a ruler as she was, or perhaps even more so. It seemed that no stallion in Equestria was quite up to the task, not even stallions from abroad fit the ticket, whether they from Saddle Arabia, Trottingham or Maretonia, no stallion was quite good enough for her.
It was getting to a point where she almost wished she'd kept Celestia around, if Celestia was here powerless and trapped she could have just cast a quick magic spell to give her sister the necessary equipment, rode her until she blew her load and then she could have sent her fat ass back to the moon. Actually... that was something she hadn't considered, if no stallion was good enough then perhaps a mare could do the job, with the obligatory alteration of course. She ordered her army to repeat the process, but this time to send mares her way rather than stallions.
Rainbow Dash approached Nightmare Moon and said "Permission to speak your majesty"
"Granted" said Nightmare.
"Forgive me if I seem presumptuous your majesty, but I believe Ponyville would agree that I would be the most suitable match to aid in your desire to be impregnated with an heir to the throne" said Rainbow. Nightmare Moon was surprised that Rainbow Dash was offering herself up so willingly, but then she was the element of loyalty, so it was a tempting offer. However, the elements were powerless if they weren't united, with the exception of magic, so Nightmare Moon dismissed the idea.
"I appreciate the offer..." said Nightmare "However, I must decline. I value your position in my army too much to use you as a means to an end anyway". Rainbow accepted that answer and joined the rest of the troops for the ongoing search for a suitable candidate to go through through the mare-to-male spell. Again, the available mares Nightmare Moon was presented with were hardly A grade material, first up from Canterlot was Fleur De Lis, Nightmare Moon's army had been smart enough not to revisit the town of ponies with equals signs this time around.
Nightmare Moon said "So, Miss Fleur De Lis, what is the reason given by the city of Canterlot that they elected you as a suitable one time bedroom partner?"
Fleur cleared and throat and said "T-They said I was one of the most, if not the most, attractive mare in Canterlot..."
Nightmare Moon was furious "I am not looking for attractive mares I am looking for powerful ones! Get rid of her!"
Immediately the next candidate was brought in, a mare from Manehattan by the name of Coco Pommel. "Young mare..." said Nightmare "Tell me, why has Manehattan chosen you?"
Coco said "Well um... I'm a fashion designer and-"
Nightmare Moon stopped her right there and said "Call off the search, this is pointless and is going nowhere, send them all back to their points of origin". Nightmare Moon was extremely frustrated, she knew that she was the most powerful creature in the world but how was it that no other pony, Equestrian or otherwise, wasn't so powerful as to be a suitable subject for the next generation destined to rule over this world of eternal night? She couldn't settle for less, whatever mare or stallion she took to bed had to be the perfect fit. The pony she needed to lay with needed to be powerful, intelligent, young, fertile... what pony could have all of the attributes she was looking for? She called upon her most reliable adviser, Spike the dragon, he couldn't be left alone with Twilight in case he tried to aid in her escape.
It had been years since he first arrived and after a while he had become as a loyal as every other pony in Equestria"Dragon" said Nightmare, "I require your advise, you know of the situation I find myself in?"
Spike simply nodded and Nightmare Moon went "Well? Tell me! Does the kind of pony I'm looking for exist and if so who are they?! It can't be my sister, I banished her to the moon for a reason, she's too powerful, I need a pony who is powerful but still of a lower caliber". Spike thought Nightmare Moon's desire was a tad too specific, but he knew the right pony for the job.
"Well your majesty, it seems that there is one pony who has everything you are looking for, though I must say you will not like the answer..."
Nightmare Moon instantly caught on "No... you can't be serious..."
Spike said "I'm afraid so your majesty"
Nightmare Moon accepted that Twilight was probably the only pony who had everything she was looking for, but she wasn't going to allow her prisoner the freedom and movement required to give her a good pounding. What else could she do? Then it hit her... it was so obvious, Nightmare Moon yelled "Guards!" Guards immediately arrived, bowing before her as she said "See to it that our prisoner is well fed and in perfect health".
Twilight just sat in the middle of the cave, the magic dampening chains clamped around her legs were all attached to the walls leaving her unable to move. She was extremely malnourished, she was given so little food that the once reasonable amount of fat on her body had simply started to ebb away bit by bit, until she was practically skeletal. She hated the cruelty of her existence, the only reason she was alive was so that Nightmare Moon could rule and take pleasure in the knowledge that the only threat to her was left to rot in a dungeon contemplating just how much she had failed and wallow in her own guilt, shame and self-loathing. Everyone she ever knew and loved was now loyal to the enemy and for her, hope in Equestria had truly died, there was no saving the land or herself. She just wanted to die.
Which is why she was shocked beyond all belief when not only had her rations increased, but there weren't any rations at all. She was given all manner of wonderful food that stayed fresh thanks to magic, not to mention a multitude of different drink choices. Twilight was initially suspicious, this was just so out of the blue it had to be a trick, was it her normal rations disguised to look like tasty food? Was it magically induced hallucinations of food? Was it laced with something that might kill her? Actually, the thought that the food might kill her wasn't an entirely unwelcome prospect considering her state of mind at that point, she figured that she had nothing to lose and tucked into all the food and drink she wanted. It wonderful, it was all so wonderful, after tasting the food and drink and suffering no ill effects whatsoever she no longer cared why Nightmare Moon had allowed this and just couldn't believe her luck.
Time flew by as Twilight continued to enjoy the bountiful food and drink she was being provided with, she started putting weight back on, she looked happier and healthier, everything was perfect. It was just as she had reached a point where she was looking like her old self again, that she got a visit that she was never expecting by none other than Nightmare Moon herself, "Hello Twilight Sparkle" she said. This wasn't good, was Nightmare Moon here to mock her for being so foolish and that now she had eaten her fill she'd be taking all of the food and drink away again? Of course, how could she have been so blind? It wasn't a gift, it was yet another way to further her pain. Nightmare Moon continued "I am glad to see you are looking much better than before, you're the spitting image of the happy young pony you were when you first came to Ponyville".
Twilight said "Thanks, I suppose you're here to taunt me, break me down, take away all the food and drink and almost starve me to death again?"
Nightmare Moon couldn't blame her for thinking that, part of her even thought that would be an interesting thing to do in future, but now was not that time. "Far from it Twilight Sparkle" said Nightmare Moon "In fact for the next year I am willing to grant you all the food and drink you could ever want, total freedom within my castle, limited freedom in Ponyville because my guards will have to accompany you and that is it, granted I will have to insist you wear an inhibitor ring on your horn, but I am willing to give you all of that and more if you so wish. I want you to be happy and to be healthy Twilight Sparkle".
Twilight Sparkle was baffled, there had to be more to it than that "What's the catch?"
Nightmare Moon again went "No catch, that's what I want for you. As soon as we are finished up here, I will give you all of that of my own free will, the only thing that is non-negotiable is the inhibitor ring and the necessity to have two guards accompany you whenever you wish to venture outside the castle."
Something was clearly very very wrong here, why was Nightmare Moon being so kind to her? She decided not to look a gift horse in the mouth however and said "So... once this discussion ends... I'm free?"
Nightmare Moon nodded "Yes Twilight Sparkle... however, this is more than just a discussion..."
Twilight knew it, of course there was something, why did she think that Nightmare Moon didn't want something in return for all of this? It must have been very big and important if Nightmare Moon was willing to give her some kind of freedom for a whole year in exchange. "You see Twilight Sparkle..." said Nightmare "I intend to rule for a very very long time, however one princess cannot rule indefinitely, like any other pony I too will eventually get to a point where I will be unable to continue and thus must pass down the torch of my kingdom to a younger pony to rule so that I may retire. However, I have absolutely no intention of allowing my sister Celestia or indeed any other pony to take up my mantle, I need an heir while I am still able enough to train them in how the world works under my rule and how they will maintain it once they become the next monarch, I need descendants".
That all made sense, though their was the obvious question that Twilight needed to ask "What does that have to do with me and earning my year long freedom?"
Nightmare Moon smirked and continued her explanation "Well, the obvious answer to this particular conundrum was to find someone suitable to mate with, I've scoured the land for every possible male that had the qualities I was looking for and would would allow them the pleasure of spilling his seed inside my caverns, but no stallion on the planet met my specifications. I too also repeated the process with mares, hoping to use the so called "mare-to-male" spell on them, but again no mare was ever up to my standards... all except one that is, your pet dragon made it clear to me that the only pony who was genetically gifted, powerfully magical and also fiercely intelligent... was you".
Twilight was heartbroken, she knew where this was going, she was more horrified that even Spike had succumbed to her will. "You can't make me! Even if you cast the spell on me you can't force me to mate with you! Besides, these chains prevent me from doing the necessary... thrusts... so it's not happening!" Twilight realized her outburst of defiance may have been a bit premature as Nightmare Moon practically cackled at her.
Nightmare Moon said "Don't be ridiculous! Do you think I'd allow you your freedom if you were the one that was going to sully my exquisite nethers with the contents of your balls? Preposterous! No Twilight Sparkle, it is very much the other way around, you are to carry my child, once I deliver the contents..." Nightmare Moon paused as she lit up her horn, surrounding her body with magic, her skin shifted as her vagina closed up and practically vanished and the glow of her magic intensified which brought forth in her vagina's place a long, thick jet black stallion cock accompanied by a pair of massive balls. Once the transformation was complete, Nightmare Moon completed her sentence "... of my balls".
Twilight was deeply against this, but she doubted her consent had anything to do with it, Nightmare Moon would end up raping her one way or another. Nightmare Moon said "Now... I think we've had enough talking, so why don't you be a good little pony..." Nightmare Moon thrust her flaccid dick in front of Twilight's face "... and get this thing hard enough for the impending penetration hmm?" Twilight simply opened up her mouth, then as soon as a single inch was pushed into her mouth, she bit down as hard as she could, needless to say, Nightmare Moon was not a big fan of the pain Twilight was inflicting on her new genitalia.
Nightmare Moon groaned as she prized open Twilight's mouth with her magic and withdrew her cock, intensely angry she screamed at her "Bitch!" then decided that violence was the best course of action. She whacked Twilight around the head with one hoof and the clattering sound of something on the stone floor alerted Twilight to the fact that the force of the hit she took had actually broken off her horn.
"My horn..." Twilight whimpered "My horn is-" Twilight didn't get to complete her lament as she received another hit that knocked out a tooth, then another that made her nose start to bleed and then another until Nightmare Moon decided she had roughed Twilight up enough, Twilight simply sobbed as blood dripped to the floor and tears ran from her bruised eye.
Nightmare Moon calmed down, she magically picked up Twilight's horn and decided to ram in into Twilight's rear, Twilight gasped and stood straight up, her face sweaty from the stress of the whole situation. Nightmare Moon said in an almost motherly tone "Listen here Twilight Sparkle, it may be hard for you to believe this but I don't actually want to hurt you no matter how much I enjoy it, I want your freedom and happiness but I can't give that to you unless you cooperate with me. All it will take for you to earn a year of almost anything you want is one ejaculation, don't make this harder than it needs to be OK?"
Twilight nodded, it would be slightly silly for her not to take that deal, even if she had to carry Nightmare Moon's child. "Good" said Nightmare Moon, she removed Twilight's horn from her butt, then using magic she fused her horn and tooth back in their rightful places whilst healing her broken nose and bruised eye, Twilight looked as right as rain. "See? I can be nice" said Nightmare, the pain in her cock had dissipated and so brought it back in front of Twilight's fate "Now, let's try this again, properly this time" said Nightmare.
Before beginning Twilight simply said "B-But I'm a virgin... I was saving myself for someone special..."
Nightmare Moon didn't have time for this and in an exasperated sigh went "Believe me Sparkle, I am currently the most special pony in Equestria and also the world, your virginity is soon to be a thing of the past, so please stop blathering on about things that are of little to no consequence and suck my cock!" Twilight obediently opened her mouth and allowed Nightmare Moon to slide her soft-but-not-for-long dick into the warm wet confines of her mouth. Nightmare Moon just hummed in satisfaction as she felt the hot and moist embrace of Twilight's mouth around her dick, she practically shuddered when Twilight began sucking, lightly bobbing her head back and forth "That's right..." said Nightmare Moon, part of the enjoyment wasn't just the forced blowjob, but the fact that Twilight was now so broken. Nightmare got a certain thrill that Twilight was not consenting to any of the sexual activity she was about to engage in with her but was sacrificing that choice anyway for the sake of freedom. It was cute in a pathetic sort of way.
Very soon, Nightmare removed herself from Twilight's mouth, she was hardening rapidly and knew Twilight wouldn't be able to hold the entirety of her erect cock in her mouth and throat... her pussy however... Nightmare moved around behind Twilight before hooking her forelegs onto Twilight's shoulders. Twilight closed her eyes and kept silent as tears continued to stream down her face, how had her life come to this? Right now she wasn't sure if the freedom was worth it, she questioned whether or not it would have been better to just simply lay down and die, starve herself to death, not allow the continuation of Nightmare Moon's bloodline. She'd become a martyr of some sort if she sacrificed her life in the hopes that Celestia would return and restore peace, but it was a long shot, she knew Nightmare Moon could find another powerful pony if she wanted to... even if took wasting much of her energy on a high level spell that would compel the most powerful pony in the world to arrive at the castle, such a spell did unfortunately exist.
Twilight no longer had time to ponder her situation as Nightmare Moon began pressing the head of her cock against Twilight's pussy, only to find she was having trouble penetrating. Nightmare hadn't anticipated that her spell might give her a cock too large to fit inside such a tight pussy, she knew it was possible that it might not fit but she had to try and repeatedly pushed more and more forcefully in an effort to enter Twilight's pussy. The strain of the attempts were making both of them uncomfortable, Nightmare was on the brink of giving up when finally Twilight's folds separated just enough for the head to squeeze inside, Twilight groaned at the mammoth stretching her pussy was undergoing and Nightmare grinned as she found that, although slowly and with a great amount of muscle power, her cock was slowly descending into Twilight's insides. The process of inserting herself inside Twilight proved to be a rather arduous task, she was barely one inch inside before she reached her first barrier, the hymen. Nightmare Moon took a short rest before again groaning as she heaved her hips forward, getting her dick inside Twilight was almost as tough as trying to fit a square peg in a round hole, the two just weren't meant to go together and trying to make it work was practically a stressful endeavor.
Nevertheless, Nightmare Moon persevered and the head of her cock burst through Twilight's hymen, claiming her virginity. Twilight did her best to remain quiet as she continued to allow tears to fall from her eyes and onto the ground beneath her, but she gasped when she felt Nightmare's Moon's cock press against her innermost barrier, her cervix. Nightmare Moon was initially disappointed, she only had half of her gargantuan member inside Twilight and she was struggling enough as it was... however, no better depository for her seed than directly into the womb, why should she quit here? Nightmare Moon tightened her grip on Twilight's shoulders and kept pushing, refusing to let something as trivial as the cervix stop her from getting the whole thing inside. Twilight as shocked and above all in tremendous pain, she couldn't believe that Nightmare Moon was actually trying to get through her cervix, getting inside her pussy had already been hard enough, was she really expecting this to work? She wanted to complain, but found the strength to stay silent, it was the best she could do in such a situation.
Nightmare Moon was becoming enraged and sexually frustrated. She leaned forward and roughly bit down on Twilight's left ear, drawing blood, in some attempt to gain more leverage, much to her surprise, it actually worked. With her hips pushing so hard and forelegs pulling Twilight back, the minute additional effort of pulling Twilight with her mouth was just enough for her dick yet again to enter a space that upon first glance was simply to small for such a thing, but there it was, Nightmare Moon's cock had now entered Twilight's womb. The squeezing Nightmare Moon felt around the head of cock was almost painful, Twilight's cervix was squeezing her like a vice. Again, Nightmare Moon had to take a rest before continuing before... oh for fuck's sake! Nightmare Moon was getting pissed off at just how difficult the simple act of raping someone was becoming, now the medial ring was giving her trouble, it was only slightly thicker than the rest of her dick and yet it still stuck outside and not entering the hole she was currently almost balls deep in.
Nightmare Moon didn't have time for this, she pulled back slightly and gave her first and hardest thrust, successfully jamming the medial ring inside, finally after some pushing she was as deep inside Twilight as she could get, her round heavy balls snuggled up against Twilight thighs and the base of her cock gone from vision, leaving only the sight of her hips pressed right up against Twilight's ass. Nightmare Moon released Twilight's ear shortly before healing it, then started to fuck her. Twilight groaned, there was a tiny presence of pleasure there, but it was vastly overshadowed by Twilight's physical and mental turmoil, her inside were abused and stretched, molding her in order to cope with something so large being inside her, her stomach actually bulged outwards obscenely with the distinct shape of a stallion cock almost threatening to burst through her torso if it went any further.
Nightmare Moon on the other hoof was having a whale of a time, the hole she was fucking was tight yet malleable, warm and wet, the clapping of balls against Twilight's thighs matched only by the sloppy moist sounds of her dick repeatedly pounding the purple pony beneath her. Considering it was Nightmare's first time owning and using a penis, she lasted surprisingly long, but alas all good things had to come to an end, Nightmare Moon practically screamed in the royal Canterlot voice, ringing out through the caves and almost deafening Twilight as her balls churned and her cock throbbed. A full two liters of spunk crashed against every wall of Twilight's uterus, bloating her belly to an almost ridiculous degree. Pregnancy was guaranteed. Nightmare Moon was panting and sweaty, she waited for her release to finish before deciding it was finally over and with a great amount of tugging she freed herself from the grip of Twilight's body, leaving only an immeasurably gaped pussy leaking sexual fluids, excess cum and blood. Nightmare's cock and balls simply vanished after that, restoring her original female genitalia, the spell wearing off once she had removed the colossal cock from the moist caverns of Twilight's destroyed cunt.
As Nightmare Moon left the dungeon, she said "Thank you Twilight, your contribution to my reign will be written in the history books for years to come. Guards, prepare the prisoner for her freedom".
In the first couple of months of being released, Twilight had tried on several occasions to flee and find help or was actively trying to make sure the baby growing inside her didn't exactly make it to term. Nightmare Moon had expected this of course and had several contingency plans in place to stop Twilight from escaping, killing the baby or killing herself, she had thought of everything. Halfway through the year, Twilight gave up and figured that since she was now free, she might as well enjoy it... and she did. She laughed and chatted, she became maternal, ate lots of food and drink, she was like a normal pony again. The only thing that disturbed Twilight was not the affection for the baby, that was natural, but her odd attraction to the one who had put the baby there in the first place... Nightmare Moon. Stockholm syndrome wasn't part of Nightmare Moon's plan, but she welcomed it, it would be great to see the look on Celestia's face to see that not only had Equestria gained a newer, younger and more powerful leader, but that her faithful student had fallen prey to her sister to a point of being in love with her. That is of course, assuming Celestia ever escaped.
Twilight wasn't exactly bi or lesbian however and she had repeatedly pleaded with her lover, Nightmare Moon, to make the cock and balls she used a permanent fixture. Nightmare refused, but agreed to put them there whenever she was stressed out and needed relief or was simply in the mood for sex. The pair had done everything from blow jobs to anal and things were going according to plan even better than Nightmare had hoped, then one day, the baby decided it was finally time to break free. The birth was surprisingly easy and painless, most likely due to the fact that Nightmare Moon had previously fucked Twilight's insides open made muscles so weak they couldn't stop anything coming in our out. The result was a perfect little alicorn colt with dark purple skin, deep blue eyes that had a round-ish slit as a pupil and the same color of blue hair that was wavy but not ethereal, a prince of the night if ever they saw one. Nightmare Moon decided to name their son Kawani-Bulan for two reasons, one being that in ponish it translated to "Malevolent Moon", the second being a cruel and ironic joke, the name came from the language of the ponies that lived in the province of Jacanter, they spoke SUNdanese.
As years passed, a lot of things changed, Nightmare Moon had been prepared to send Twilight back down to the dungeon, only to find that she didn't really need to. Twilight had no desire to escape and had practically forgotten she even had magic even since being force to wear the inhibitor ring, the guards never seemed to report back with her acting any different to any other day, so either Twilight was playing the long game or she was simply content with her new life. However, Nightmare Moon couldn't take the risk that Twilight might secretly teach their son about harmony and love and all that useless nonsense and so, though it did actually pain her to do so, she kept their son shielded from the possible influence of Twilight's good-hearted nature. Their son had to be a hardened, cold and unfeeling prince if he was to inherit the throne, it was once Nightmare Moon explained that to Twilight that she understood and promised to stay away from him, no matter how much it hurt.
Of course as time passed, the prince grew more and more each day and Nightmare Moon taught him and trained him, shaping him to becoming the perfect ruler that would one day be able to defeat his aunt with ease should she ever return. Of course, other ponies grew old as well and the unfortunate event occurred where Twilight, his mother, simply died of old age. Nightmare Moon was somewhat heartbroken, she had to admit that she had grown unusually fond of Twilight during their time together, this however presented the perfect opportunity to test whether or not her son Kawani could be the iron-hoofed ruler that she had trained him to be, the one who would ensure that the night would last forever throughout Equestria and the world. She delivered the news of his mother's death to him.
He was shocked and of course felt a sense of remorse, but said in his booming voice "It is... regrettable... that such a fine pony should pass away and of course, a funeral will have to be arranged at some point, however that is not to say that such a tragedy should affect our current course". Perfect. Soon after that, Nightmare Moon decided she needn't continue to rule and retired early, abdicating the throne so as to make way for the coronation of the newest prince of Equestria, land of eternal night, prince Kawani-Bulan. He was just as strict a leader as Nightmare Moon was, perhaps even more so, he would certainly be able to rule for a long time before he himself would have to think about siring his own heir, there was only one challenge that arose though. It took around one thousand years, the same as it had for Nightmare Moon, but Celestia did eventually return, though not as herself. The creature that claimed to have been freed from the moon by the stars was what looked to be some kind burning pony demon that called herself "Daybreaker", prince Kawani had been trained to fight Celestia upon her return, not some raging beast version of her.
Which is why it made perfect sense that when "Daybreaker" decided to make a dramatic villain entrance into the castle, she was killed instantly. Sure it wasn't the traditional Celestia, but it was still her underneath all the anger and fire, she didn't stand a chance, the army and the prince were just more prepared than Celestia or Daybreaker or whatever had anticipated. What happened a few years later was something that nobody could have predicted, the prince was pondering the future, specifically when he would pick out a mare to impregnate to continue the monarchy. He knew that like his mother Nightmare Moon before him, he had to pick someone who was intelligent and powerful so as to produce the best offspring. The situation was awkward however, because he came to the conclusion that if he trod in the hoof steps of his mother, then there was really only one logical pony to breed with, the most powerful pony other than him, Nightmare Moon herself.
When Kawani confronted his mother about this, she said that he would of course have to settle for some other powerful pony, though the awkwardness of the situation didn't stop them from tumbling into bed together for just one bout of passionate sex, which fortunately didn't lead to a pregnancy. Suffice to say though, the night would truly last forever.
