Kazuki entered the dojo where Moon was waiting for him after informing Song and Jewel that this mission shouldn't take more than a few hours and leaving them in charge while he was out. He entered the dojo and saw that Moon was sitting on her zabuton and ready to go, so he sat on his zabuton, looked at her and nodded. Both of them took a deep breath and allowed their minds to slowly disconnect from their bodies.

Canterlot Castle

Kazuki and Moon appeared on the tallest tower of the Castle, they looked exactly like they look normally except they were slightly see through. This was their astral projection and they were observing as the guests were arriving, nobles and dignitaries of Equestria and beyond.

“So what we should do?” asked Moon using a voice that couldn't be heard by normal beings.

“I will activate the tags I placed all over Canterlot and that will cause their sleep cycle to become more intense and it will also muddle the Dreamscape, just enough for us to move undetected,” explained Kazuki.

“So you will basically give nightmares to everyone in the city to distract Luna,” said Moon.

“No, just increased the intensity of their dreams no matter the type. Besides this also has the secondary effect of placing a hypnotic suggestion deep within their minds that could be used on a later date,” said Kazuki as he observed with amusement the events happening on the entrance.

Moon saw the smile of amusement on Kazuki's face and she almost did a facepalm when she looked at what was so amusing to him, on the entrance was the Mane Six, but that's not what embarrassed her, no what embarrassed her was the fact that the ponies below started to sing and dance as if they were in a perfectly choreographed musical. This was one of the most embarrassing traits of her kind in her opinion, their propensity to suddenly burst into songs and dances.

“It's always amusing to see the way their inner magic and herd mentality interacts. Don't you think so?” asked Kazuki and his only answer was a groan. They stayed there until the musical number was over and when it came to an end Kazuki said, “Ok, that’s enough stalling. We must go to the Shadow Realm.”

Moon nodded and they disappeared from there, at least that was what seemed to have happened from the perspective of those that were capable of seeing them –not that there was anyone capable of seeing them there at the moment– because from Moon and Kazuki's perspective the world around them changed.

Their surroundings still looked like Canterlot but with the colors faded and drifting out of their respective objects like something between oil or ink in the water or smoke in the air and the guests now looking just as faded but with their outlines surrounded by a glowing smoke/oil like aura the left a faint trail, that was another layer of the Mindscape known as Shadow Realm or Shadowscape, the “shadow” of the physical realm.

Kazuki went through a sequence of hand seals before ending in the Dragon Seal and say, “Musōinjin(六蒼陰陣, Six Blue Yin Formation).”

A blue hexagonal barrier was erected around Canterlot, however it was only visible in the Shadowscape and thus went unnoticed by the inhabitants and visitors in the city. This was a technique he made based on another barrier, the Musekiyōjin(六赤陽陣, Six Red Yang Formation) but as a spiritual barrier instead of a physical one.

After setting the barrier Kazuki jumped from the tower and Moon wordlessly followed him. They phased through the ceiling and the rooms below until they landed on a hallway and from there they walked to the ballroom. They passed a few guards that were patrolling the halls, however they were not in the physical plane, so they went mostly undetected, but few of them seemed to have good instincts and felt that something was there even if they couldn't see the invaders, so just to be sure Kazuki and Moon hid anyway.

“It still amazes me how much there was to the Dreamscape that I didn't know,” said Moon as she and Kazuki walked on the ceiling toward the ball room, then she stopped when she saw a shadow near one of the corners and asked, “What was that?”

Kazuki looked around before activating his Rinnegan, the he reached out and grabbed something, then the air started to distort until a grotesque creature made of shadows with multiple eyes glared at Kazuki as it trashed the surroundings only for it to be back to normal a moment later, then Kazuki released the creature and it darted to another dark corner and disappeared.

“Let's go,” said Kazuki as he continued to walk as if nothing was wrong, but kept his Rinnegan activated just in case.

“What about that creature?” asked Moon still looking at the corner that it disappeared.

“It's just a natural inhabitant of this layer, a shade born out of negative emotion(s) left behind by someone. The closest equivalent would be the nightmares in the Dreamscape,” said Kazuki and Moon nodded wanting to focus on the mission for now.

When they arrived on the ballroom they saw the glowing silhouettes of the guests, most of them were ponies but it was possible to see few minotaurs, gryphons, goats and zebras, but the brightest silhouettes were the Mane Six. Despite that fact they almost missed Twilight since she was standing beside an even brighter silhouette, this was Celestia.

“To think those six had such potential,” said Moon understanding the significance of their brighter auras.

Ignoring Moon’s statement Kazuki carefully weaved around the room to reach Celestia, Moon would have questioned his paranoia since they could just phase through the guests, but then she saw some guests look around in search for something before briefly stopping on them. Seeing that some of the guests had affinity for mind magics be they minor or greater she conceded and just followed his lead.

Eventually they arrived on the center of the staircase where Celestia was greeting the guests and Twilight was beside her looking bored, they slowly circled around the two ponies, but suddenly Kazuki motioned for them to stop.

“Is it something wrong my faithful student?” asked Celestia, her voice a little distorted by the “air” of the Shadowscape, probably sensing something, but it was more out of instinct than affinity for mind magics since her affinity was to the sun and thus Yōton(陽遁, Yang Release), which was associated more with the physical realm instead of the spiritual.

“Nothing, I just thought I saw something in the corner of my eye,” said Twilight as she unknowingly stared into Kazuki's Rinnegan and was none the wiser.

Kazuki offered his right hand to Moon and placed his left index finger over his lips, after realizing what he meant she grabbed his right hand with her left. Then he slowly reached out to Celestia from behind freezing every time he saw Twilight's eye twitched at his direction, the shadows one could see on the corner of one's eye were more often than not brief glimpses into the Shadowscape after all.

When Kazuki managed to touch the back of Celestia's head he fell forward as of Celestia suddenly became a hole in reality and Moon was pulled with him. Now they found themselves falling into what seemed an endless abyss and it was this moment Moon let go of Kazuki's hand.

Both of them did a flip and landed on the surface of wherever they were, then Moon looked around and saw the ballroom. Indeed they landed in a exact replica of the ballroom but with normal colors indicating that they were back into the real world, however the place was empty.

“Wha-” started Moon but she was cut off by Kazuki raising his hand in a clear sign for her to stop talking. Then he deactivated his Rinnegan and activated his Byakugan to look around them.

“It's safe to speak,” said Kazuki as he deactivated his Byakugan, however he activated his Rinnegan again but this time on his third eye, which left his normal eyes free to use the Byakugan if needed. Using two Dōjutsu on the same eye could be quite straining and using just one Byakugan would only widen the blind spot on his vision.

“I thought we would invade Celestia's mind, why are we back into the real world?” asked Moon no longer bothered by Kazuki's third eye looking around the room independently from his main eyes.

“Look closer,” said Kazuki and Moon did so. The first thing she noticed was that it was day instead of night, at first she thought it was just her eyes still getting used to the light of the real world, then she saw that the room was without any decorations both the usual ones and the ones placed for the Gala. However the most telling fact was when she looked out the window she saw the sky like it was in the day, but when she looked down she saw a huge jungle and the castle was on a floating island.

“We are in Celestia's mind, it's just that it took the form of a place she is familiar with and considering that she lived in this castle for millennia…” said Kazuki before trailing off and letting Moon filled the gaps herself.

“I see,” said Moon as she followed Kazuki as he entered the hallway.

“Anyway, we have a few hours to accomplish our objective since this place works with a similar logic to dreams,” said Kazuki and Moon nodded.

“So, were to?” asked Moon.

“Probably the dungeon since this place is more metaphorical than real so everything here is up to Celestia's own interpretation, so we–” Kazuki was started to explain but stopped turned around and activate his Byakugan. Immediately he jumped up and used his hair to wrap around Moon waist pulling her with him, the moment she opened her mouth to express her surprise some of the free hair wrapped around her lower face.

Moon struggled and glared at her captor that was crouching on the ceiling and looking “up” with his Byakugan, he placed his right index finger over his lips before pointing “up”. When she looked down she saw a pair of guards walking down the hallway and the two infiltrators stayed silent until the patrols passed, then Kazuki jumped down and gently lowered Moon before unwrapping his hair.

“Did you really have to go all tentacle on me?” asked a little annoyed and bit curious about the possibilities that presented for their “activities” in the bedroom. Then she asked, “Who are those guards anyway?”

“They are kinda like constructs, not unlike in a dream. They are projections of Celestia's experience and defenses, if anyone sound the alarm then Celestia will immediately be aware of our presence. However their presence is a good sign, the more well guarded a location or item is the more important it's for Celestia,” explained Kazuki before doing a hand seal and be engulfed buy a puff of smoke.

When the smoke cleared Kazuki was wearing somewhat loose black clothes with the end of the sleeves wrapped and tucked inside a pair of black vambrace or arm guards, the cuffs of his pants were tucked inside his Jika-tabi(地下足袋, tabi boots) and his head covered by a mask with a opening only for his three eyes showing his still active Rinnegan and Byakugan and on the back of the head for his hair, which was done in three braids with a kunai on the end of each braid that were also strapped onto his belt, a belt that had two ninja pouches on each side. All in all what you would think a shinobi shōzoku(忍び裝束, shinobi attire).

“You should change to your infiltrator gear,” said Kazuki and Moon just reached into her pouch on the right side of her belt and took out two vambrace, then she just rolled the sleeves of her kimono around her forearm before placing and strapping the vambrace over it. Kazuki just raised an eyebrow and commented, “That's very practical of you.”

“This coming from someone who wears expensive clothes most of the time,” snorted Moon as she turned her mist like mane into a bun and doing the same with her tail as they proceeded to the dungeon through the seemingly deserted hallways.

“And as I said before, I appreciate art and that also includes clothing and it so happens that all clothes I use were made by my own hands,” said Kazuki in a almost indignant tone.

“It still amazes me how many domestic skills you have and how frivolous they are, despite their more nefarious origins,” said Moon shivering in the end.

“And as I said before sewing, stitching and weaving can work as easily with living tissue as they do with fabric,” said Kazuki casually, which once again caused Moon to feel shivers running down her spine.

Kazuki motioned for her to stop before they silently climbed on the walls and reached the ceiling where they saw two guards on each side of the entrance to the dungeon. Moon nodded and pulled a face mask that was hidden around her neck over her lower face before crawling along the ceiling keeping herself there using the tips of her fingers and tip of her hooves like Kazuki taught her, while at first she found somewhat humiliating to crawl like this she couldn't deny its effectiveness.

Moon moved until she was right over the guards, the she extended her mane down and like a snake she coiled it around their mouth and neck before constricting it until a sickening crack was heard. Just as their limp bodies were hanging they slowly started to fade until they disappeared, then Moon retracted her mane and remade it into a bun before coming down and met Kazuki in front of the door.

“Is it really ok to kill them?” asked Moon as she checked the door for traps.

“Hai, most of the projections anyway. They are kinda like the nameless faces in the crowd and she would only noticed that something was wrong if she was either meditating or if she wasn't distracted, however we have to avoid contact with the more important ones, the ones she knows and has a personal connection with,” said Kazuki and Moon nodded before giving a ok.

They opened the heavy door and looked at the dark corridor with empty prison cells on both sides and Kazuki said, “Ok, that's unexpected.”

Real World, a few minutes later(many hours later in the Shadowscape)

Celestia was entering the donut shop to have a snack with the Mane Six and Spike after the Gala, which the young mares made more interesting in Celestia's opinion, since they had a little bit of time before returning to Ponyville and before she would retire for the night, for some reason she felt a little more tired than she expected but she just brushed that off.

“That was the best Grand Galloping Gala ever!” said Celestia enthusiastically as she sat on a free seat on the big table.

“Princess Celestia!” shouted everyone in surprise.

“Pardon me, Princess, but tonight was just awful,” said Twilight with sadness evident on both her tone and face thinking she disappointed her mentor.

“Oh, Twilight. The Grand Galloping Gala is always awful,” said Celestia as she thought on the yearly event she participated for millennia since the founding of this city.

“It is?” asked Twilight just as confused as everypony, Spike on the other hand was just enjoying his donuts.

“That is why I was thrilled you were all attending. I was hoping you could liven things up a bit. And while the evening may not have gone as you planned, I'm sure you'll agree that in the end it didn't turn out so bad for this group of friends,” said Celestia as she clapped her hands together and smile, but on the inside she remembered the few beings she truly called friends over the ages.

“You're right, Princess. Friends have a way of making even the worst of times into something pretty great,” said Twilight phrasing in the same way she did her friendship reports.

“Yeah!” shouted Rainbow before placing her hands on the table and getting up of her chair, then she continued, “Hanging out with friends!”

“Talking!” shouted Fluttershy, which was normal volume for everyone else.

“Laughing!” shouted Pinkie as she got up on the table not bothered by her stained dress.

“You mean doing exactly what I wanted to do the whole time?” asked Spike with a smug tone after swallowing the donut he was eating.

“Yes, Spike. You were right,” said Twilight rolling her eyes but smiling at her little brother/assistant.

“As horrible as our night was…” started AJ.

“...being together here has made it all better,” finished Rarity without being bothered by her strained dress as well.

“In fact, it's made it…” started Pinkie back on her chair.

“...the best night ever!” finished the Mane Six getting up and toasting with their glasses of soda.

Celestia just watched as her pupil and her friends laughed together and that made the princess think about ages long gone when she did the same or when she watched her own mother and her mentors do the same in ancient times.

“Are you alright, Princess?” asked Spike noticing that Celestia was zoning out.

“Yes Spike, just old memories,” said Celestia to the baby dragon in a tuxedo before addressing her pupil and ask, “So, how is your stay in Ponyville treating you, my faithful student?”

“Well…” started Twilight a little embarrassed but she immediately started talking about all the excitement that she experienced over her stay in the small town.

Celestia listened to her pupil’s tales with comments by the rest of the Mane Six and Spike, but eventually she had to ask, “Have any of you made contact with the mage that set up shop in the Everfree Forest?”

“No, but I met some of the diamond dogs in the tunnels and they just made sure that I wouldn't enter the tunnels that led to their den, aside from that they let me and Spike collect gems in peace. I even managed to have a civilized conversation with some of them, and let me say that they are far more educated and well-mannered them those brutes that foalnapped me,” said Rarity after a while.

“Mah sister also said that Zecora knows whoever is there,” said AJ.

“He also has two dra– dragons, huge, gigantic, terrifying, enormous, teeth-gnashing, sharp-scale having, horn-wearing, smoke-snoring, could eat a pony in one bite, totally all grown-up dragons,” whispered Fluttershy as she trembled and tried to hide under the table as she listed the features of the dragons.

The group got apprehensive and Rarity comforted the fearful pegasus before mentioning, “Also Sweetie mentioned that Zecora calls him ‘Honorable Sage’.”

“Honorable my flank,” mumbled Rainbow still annoyed at the diamond dogs and whoever was commanding them.

“A Sage!” shouted Twilight after doing a spit take with her soda all over Pinkie, who just used her mane as a windscreen wiper on her eyes and stood there as if nothing was wrong. Then Twilight continued, “Why nopony told me he was a sage?!”

“What's the big deal egghead?” asked Rainbow.

“A Sage is someone who managed to achieve 'balance and oneness with nature’ and they used not only their internal reserves of magic but also magic from the environment directly and they are incredibly rare,” said Twilight before going on and on about everything she read about sages.

“At least this explains his reclusiveness,” said Celestia and seeing the look of confusion on everyone, except Pinkie, she explained, “Sages are more often than not hermits preferring to be in constant contact with nature. Then it's no wonder he wants to remain isolated.”

Rarity looked at a clock on the wall of the store and saw how late it was, so she said, “I hate to interrupt you Princess, but we better go now if we want to catch the last train to Ponyville.”

After that the Mane Six said their farewells to the Princess and Donut Joe, also thanking the stallion for allowing them to stay that late in his shop. Celestia also said her farewell to the stallion before heading to the castle to retire for the night, she might catch her sister before her nightly patrol on the Dreamscape and after her court –more like free time to practice modern equestrian.

Celestia's Mindscape, few more hours later(few more minutes on the real world)

Moon was groaning in frustration as she paced around the library of the castle. Then she said, “It has been a day, more than a entire day in fact! We checked the dungeon only to find it empty, then we checked the vault only to find some secrets but nothing major, then we checked the kitchen and found a secret passage with only a few embarrassed and/or kinky memories and fantasies involving cake, then we checked the towers, the barracks, the armory and lastly the library!”

Moon threw a book in frustration but Kazuki, who was without his mask, caught before it could hit anything and placed it back on the shelf while Moon continued, “We found some secret passages that led to memories and similar things, but still no sign of the darker side! You even had to use that dōjutsu after we managed to avoid the guards!” then Moon sighed and took a few deep breaths to calm down before asking, “Where is she?”

Kazuki looked around to make sure there was nothing hidden before moving on, the eye on his forehead still supporting the Rinnegan but his normal eyes were no longer lilac colored with bulging veins around its sockets and instead were very normal looking but the iris was a solid almost glowing cyan color, this was the Jōgan(浄眼, Pure Eye) a evolution of the Byakugan and capable of everything its predecessor could do plus the ability to “search for the flaw in everything”.

“Indeed, we checked everything that was heavily guarded. I'm seriously considering in declaring this mission a failure, but at least we accomplished the side-objectives,” said Kazuki before he placed his right index finger on his chin while having a thoughtful look, “It's unlikely that she managed to balance herself with her darker side, so it means it's locked in a placed that there is no need for guards. Where in this castle she could hide something and be able to easily check it and also be sure that it won't escape?”

After some thought Kazuki managed to reach a conclusion, so he informed Moon after putting his mask back on, “There is one last place we can check, if it's not there we consider this retrieval mission a failure.”

“Were to?” asked Moon as she followed Kazuki out of the library.

“Celestia's room,” answered Kazuki.

From there they proceeded through the hallways and sure enough they noticed a increasing number of guards the closer they got to the wing where Celestia's room was located, it was easy to avoid them but they had to kill two guards on the door of the room. They died when Kazuki fixed one of his braids on the ceiling before coiling it around one of his legs and like a acrobat of a circus he lowered himself, then he stabbed the guards in the heart from behind with the kunai on the tip of each of the remaining braids.

From there Moon proceeded to temporarily disarm the spells present on the door, which took another hour, before opening and entering. The place was a big room, very similar to Kazuki’s own room in his castle, but Celestia's room had a custom made four-poster bed, on the right side was a fireplace and left side was a desk and shelves with books and scrolls.

In front of the fireplace was a purple carpet with some cushions, on the right of the fireplace was a window, after the entrance was a tapestry depicting Luna and Celestia and seemed to be from before her banishment, after the desk and shelves was a vanity mirror and beside it a door that probably led to a bathroom and lastly after the bed was another door but this one leading to a balcony.

They search every nook and cranny of the room and unlike before they didn't find anything not even with Kazuki's Jōgan. They were about to give up when they felt and saw the world around them shimmer for a brief moment.

“What was that?” asked Moon.

“Celestia is asleep, now if we were to be found out we would have to deal with both Celestia and Luna,” answered Kazuki.

“We better cut our losses,” suggested Moon.

Kazuki was about to agree but a second shimmer passed indicating that Celestia’s mind was starting to connect with the Dreamscape and soon she would start dreaming, but that might take a few hours in the Shadowscape’s time, however as he was turning he noticed something near his blind spot the moment the second shimmer happened. Instead of answering Moon he crouched down beside the bed and reach into its shadow managing to go past the floor.

“It seems we found it,” said Kazuki before laying on the ground, grabbing the edge of the shadow and pull himself under the bed.

Moon went to the other side and did the same with a bit more difficulty since her breasts were pressing on the ground and she felt her butt brush against the frame of the bed.

Once they were both under the bed they were both hanging from the edge of the square opening under the bed, they looked down and saw a black abyss, then they look at each other and nodded before letting go of the edge. They fell, but not long after they landed on the floor and by the sound end feeling they landed on a platform of stone. The place was pitch black outside of the square illuminated by the light coming from the entrance, them the entrance closed.

Torches started to light up revealing a hexagonal room with a prison cell on each facet, there was also two more levels above them, apparently with six more cells, with one cell on each facet.

“Well well well, look what we have here,” said a voice from one of the cells.

“So that's how she managed to keep her darker side under control,” thought Kazuki to himself.

Both Moon and Kazuki looked at the source of the voice and from the darkness of the cell a pair of yellow slitted eyes with a dark red almost black sclera could be seen staring at them.

Author's Note

I took inspiration from Inception, mostly. Also imagine that they are wall crawling like Spider-Man.

The Shadowscape was based on the Unseen Realm from Lord of the Rings and the Twilight from Zelda: Twilight Princess.

The prison is based on the Dark Prison from Mortal Kombat Deception but without the traps.