In a quiet little village named Ponyville, everypony was asleep as it was nighttime. All except for one lavender coloured princess named Twilight Sparkle, as she was searching her library for books relating to dreams. Twilight was always curious of how Princess Luna's "Dreamwalking" ability worked, but when she asked, Luna only responded with "I am the Princess of The Night. Ponies sleep at night and I protect them from nightmares."
This didn't satisfy Twilight's curiosity however, and now she was searching her library for answers. Unfortunately for her, all the books on the subject of dreams never covered the concept of Dreamwalking. Except for one.
This mysterious book was titled "Legend of The Star Warrior" and Twilight wasn't sure whether it was fact or fiction. It was about a legendary pink blob named Kirby who allegedly guarded the Fountain Of Dreams, the source of all dreams. She had read it as a filly and merely passed it off as fiction, but now that she was older and wiser, she had noticed a few similarities within the book and Equestria. The biggest one came on one of the last pages, where the illustration was of Kirby spreading his homeland's ability to visit dreams to various places. One of the recipients of this ability was to a small alicorn filly who looked eerily similar to Luna.
Twilight felt a sense of satisfaction as she closed the book and took it with her back to her bedroom. It had been several hours since she started looking for any clues on the origin of Luna's dreamwalking ability, and she might have just found the evidence she needed to find out once and for all.
After climbing into bed and letting herself get comfortable in her bed, Twilight used her magic to put the book on her bedside cabinet before finally relaxing and letting sleep take her.
Twilight awoke, not in her crystal castle with her faithful assistant Spike snoring peacefully away, but in a burning, semi-destroyed version of Ponyville. Looking around her, Twilight noticed a distinct lack of ponies panicking, whether they were evacuated earlier or hiding out in their homes, she didn't know. Before she could act however, a bolt of magic struck Twilight from behind, causing her to yell in pain as she fell onto her side.
Craning her head around to see her assailant, it was none other that The Great and Powerful Trixie, wearing the cursed artifact known as The Alicorn Amulet around her neck, while wearing a black cape. Something about her seemed off, but Twilight couldn't tell what.
"The Great and Powerful Trixie will defeat you once and for all Twilight Sparkle!" Trixie said in her usual boastful tone although it sounded darker, almost as if Trixie had been completely corrupted by it and would stop at nothing to see Twilight dead.
The thought made Twilight shudder "Is this what would have happened if I lost that second duel to Trixie? If she got the chance to finish me off? No matter, I shall have to defeat her, evil or not! For the sake of Ponyville!" Twilight thought while getting up slowly, the magic bolt still stinging her back.
"What's wrong Twilight? Can't keep up with me? It'll be over soon, and I'll have Ponyville underneath my hoof!" Trixie said while laughing manically.
Twilight attempted to fire a magic bolt in retaliation whilst Trixie was distracted, but it was deflected by a red shield created by the Alicorn Amulet. She tried several different offensive spells, but none of them seemed to hurt or even trouble the shield. Twilight eventually collapsed from the strain of using so many offensive spells, exhausted and panting.
"Face it Twilight, you cannot defeat me. It's time to end this." Trixie said while her horn started to glow red and slowly charge a bolt that would surely destroy Twilight as she watched in horror. As she finished charging her spell, Trixie gave one last evil glare before Twilight put her hooves in front of her face in a desperate attempt to block the incoming magic.
"MONADO SHIELD!" an unfamiliar male voice shouted. As Twilight put her forelegs to the floor, she noticed that not only was she okay, but that she had a yellow shield surrounding her general area. Turning to her right, she saw a pink blob with red shoe-like feet wearing a black baseball cap backwards, holding out a mechanical looking red sword in his right hand, with a determined expression upon his face. Examining the blade closer, Twilight noticed a strange yellow symbol in a circle near the handle of the blade, presumably the cause of the shield.
Before either pony could respond, the shield dissipated as this mysterious saviour leapt up into the air, welding his sword in both arms before shouting "MONADO BUSTER!" and slamming it into Trixie, causing a magical explosion that nearly blinded Twilight. When the blast has vanished, Trixie was nowhere to be found, but a black mist had replaced her, flying up into the sky before disappearing, much like how Nightmare Moon did years before.
"I believe we have some explaining to do." the pink blob said whilst turning around and sheathing his sword, a satisfied grin upon his face.
Before Twilight could respond, a familiar voice spoke up, making her jump slightly "Indeed we do Hclegend. Hello again Twilight Sparkle, we apologise for not arriving sooner." Luna said in a warm tone, as Ponyville seemingly returned to normal before she landed.
"I guess I'd better start with who I am. I am Hclegend, current guardian of the Fountain of Dreams and wielder of The Monado." Hclegend started as he pointed to the weapon upon his back. "What you just experienced was a nightmare caused by... Well Nightmare, the causer of bad dreams, my mortal nemesis and possibly the origin of Nightmare Moon. I still don't have sufficient evidence either way. I digress, Luna had called upon me since Nightmare can cause some serious psychological trauma if he gets too far deep within your mind, gradually eating away at you until he has complete control over your emotions through manipulation of your dreams." he explained, with a worried look on his face.
"I noticed that you were having the symptoms of a particularly bad nightmare, and I called upon the Dream Guardian in order to safely dispose of Nightmare. Because if he got into my dreams again..." Luna trailed off as her face fell slightly. They all knew what would happen.
"So... Considering that I've lost Nightmare's location again, I'd better head back to the Fountain of Dreams and make sure he doesn't corrupt it again. Pleasure meeting you Twilight!" Hclegend said before fading away, presumably waking up back at the Fountain of Dreams, wherever that was.
"I must leave too Twilight. There are many more dreams I have to check upon. Have a pleasant night!" Luna said happily before flapping her wings and flying into the moon, exiting Twilight's dream and leaving ripples in her mind.
Before she knew it, Twilight awoke back in her castle, Celestia's glorious daylight shining through windows as her faithful assistant shaking her foreleg, looking terrified. "Twilight! Are you alright?" with concern in his voice.
Twilight gave a warm look. "I'm alright Spike. Do you fancy coming with me to Canterlot? I have a bo-" she stopped as she looked at her bedside cabinet.
The book was gone.
Author's Note
Well, that was... A thing.
Yes, that's my headcanon for where Luna got her dream walking ability from. Who else but someone who originates from DREAM Land?
That was terrible.