The Night Shall Last Forever

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".