Lunanon
The moonlight up high strained more powerfully than any night. Grass littered the forest and Luna walked on the wild side. She needed some divine comfort. Somepony to tell her what she should do on these stressful thoughts enveloping her mind. Princess Luna gave a few steps forward through the brush of vegetation she came from. Using summoning magic wasn't her talent, but she needed to bring someone she held dear to comfort her. Her mane messy and her wings littered with dead feathers, she didn't even bother to do her daily preening. Off she continued while the moon watched overhead.
After guiding herself near a large pool of water near, she decided it best to summon right then. Her horn flared powerful magic and energy swirled all over herself. Dark power surged and she let loose a blast of power right into the ground. A star with five prongs emerged and a mystical being crawled out of it. Luna knew that her friend was not of this world, a being who came long ago from another dimension filled to the brim with an alien species. This lost soul who somehow arrived in this world attracted many a eye of equines, but interest came to Luna the most.
The creature pulled himself upright with the odd protrusions on his palms. After setting himself in proper stance, he opened his stirling black iris's to the goddess before him.
Princess Luna? Are you the one who tore me from my home? Back at earth?
Luna looked down sadly, she knew that doing such a thing must have been a huge disturbance, but she just didn't care. No pony would be able to understand what she is going through. They might take it away because of how fearsome this side of her is and its something she doesn't want to lose. She looked at anon with pain in her eyes and ran towards him to feel his comfort. Anon could only grasp her embrace, her head caressed by his two minotaur hands.
"Anon! Dost thou, not see'ith? The incredible pain is too much for mine self to endure."
Anon smiled happily to see his friend after all this time. Even being completely naked from the trip has forgone all shame.
Luna, whats so wrong that you bring me back after all this time?
She turned away from his embrace, he letting her go to walk back pensively.
"For you see, dear anon, I hath another part of me that I do not know what to do with."
What is this part you are talking about? Could you give me it in better detail?, asked Anon while crossing his arms.
"It's hard to explain... it is like a monster that skulks the night, always trying to seed itself through. A terrifying presence that feels monstrous, yet tastes so natural..."
Natural? Why haven't you told Star Swirl or your sister...?
"No! I can not, they might take it away from me! And it feels of the utmost importance."
Then, why are you afraid? If this feels so natural, then why don't you try to embrace it then?
"Anon, please! This part of me, is something absolutely frightening to even think about, and I am not sure what its true intentions are."
Well then, let me see it.
"See it?" said Luna questionably
Look, if you want me to help you, and if this is a part of you. Then just bring it out!
Luna scratched her head confused, releasing something like this out in the open could have any type of outcome.
"I... I'm not sure."
Come on! Don't you remember the vow we took? To always trust each other? You told me that you didn't trust anypony, but you and me, we even shook on it! Just let it go.
"Hmmph, just like your earthly customs... okay, I'll let it loose, but you have to promise me that you will be fine."
Yes, everything is going to be fine, Luna, I can take care of myself.
Luna nodded and smiled, she closed her eyes and darkness clouded the area around her. A black miasma circled her exterior and in what seemed a second, she released the dormant form within.
Luna, is that you?
The figure was dark as the black sky above. Her wings bat-like and horrific. Two sharp teeth protruding from the roof of her mouth. Her mane wavy as before, but with an odd haziness to it. Anon looked at the new form and it just smiled, showing its sharp teeth.
Who'm am I speaking to?
"Somepony new, Luna has told me much about you, Anon.", it said while walking past slowly.
What are you? You seem kind, but with an odd vibe around yourself.
"I am, but a side of your precious Luna that you've never seen before, you may not know, but she is very fond of you. Very fond of you. She even thought of... mating with such a creature, hows that for strange."
I don't believe you, that would be weird... very weird...
"Oh she is much stranger than you think, so scared of interaction... unlike me, how about I show you a few tricks...", it pressed her backside to anon's side. He quickly backed away from the endeavor with fear of what this being would want to do.
Woah, hey, I maybe friends, but I'm not gonna do that. I mean I'm not even the same species as you.
"Hah, refusing a Princess? None has had the audacity of doing such a crime, I might as well just... punish you now."
A sudden stretch, and her wet, dripping, marehood waited valiantly for his entry. Anon backed away slowly, trying his best to think of way out of this. Suddenly, the creature wailed in agony, the darkness on her skin started peeling off.
"No! I haven't had relations in so long! Not nooooow!"
With those words, the form that was became Luna once again. She opened her eyes and saw the startled Anon after turning her head to see.
"What happened? How was the other me?"
...
"What?"
She tried to have sex with me
"What!?"
Yea, and since she is a part of you, then, well...
Luna blushed feverishly, embarrassed beyond belief, she lit her horn with her dark magic.
"Wait, Luna, we can talk about this!"
She blasted Anon right in the chest, where he started getting tinier and tinier before evaporating back to his home at earth.
Luna stretched her wings and flapped high into the sky as far away from the forest as possible. The sight of Canterlot Castle was a dream come true.