Save the Dragon from Himself
Twilight and Luna ran through the castle. Twilight had called on the alicorn of night when Spike had fallen into a deep sleep, and Zecora had been unable to help. With Luna's help, the two alicorns cast themselves into his subconscious. However, Twilight wasn't prepared for the twisted, creepy landscape within.
Spike's voice, distorted, sharp, pained and painful, echoed all around them as they navigated the halls. Exaggerated, clingy caricatures of Rarity flung themselves at them, assaulting the mares with magically-created gemstones. They spoke in unison, "you will not harm our precious Spikey-Wikey! He who commands the respect of all!" Wherever the gemstones fell, crystal ponies rose from the ground, each wearing "Spike The Brave And Glorious" shirts. Twilight kept a shield around herself and Luna as the night mare navigated through the hallways.
"As weird as this is to say," Twilight shouted over the din of crashing crystals and shrieking mares with white coats and flowing, purple manes, "thank you for not telling me we have to kill Rarity."
"Your gratitude is appreciated but misguided," Luna called back, using her own telekinesis to guide Twilight quickly through a sharp corner, "would we not be immediately overrun, I would welcome the chance to train you in dream fighting." A gem struck the carpet before them. The pair leapt over it as it formed a crystal pony. Luna cast a spell as a Parthian shot; it struck the newly-made mare, causing her to continue to develop into a thick, crystal wall as they fled, sporting numerous eyes, limbs, and semitransparent cutie marks.
The purple alicorn looked back and shuddered, pure muscle memory forcing her to keep galloping on. "What kind of spell was that?!"
This time, it was followed by a soft, pleading "no... don't..." in Spike's normal voice.
"Dreams need not make sense, Twilight Sparkle," Luna replied as they came to a door. There was a rough-cut, heart-shaped hole in it, where a lock would be, and the alchemical symbol for fire printed above it. "As often as I disagree with the draconequus, adapting chaos magic from Discord can be helpful in a pinch." She squinted at the door. "A fire-attuned heart? Twilight, you are Spike's guardian. Do you know what would fit here? Something deeply related to his sense of identity."
"this isn't right... i would never..."
Twilight racked her brain, running back through her memories of Spike, growing up with him, watching him figure himself out. Not the Crystal Heart, it was too big. Not a Power Ponies book. Not that bowtie from the incident with Owlowicious. The mare gasped. Rarity! "It's a fire ruby! He was going to give it to himself for his hatchday, but gave it to Rarity instead. When he went into Greed Growth, she refused to give it over to the rampaging... Spike, and that helped bring him back!"
"if she's screaming, that's not..."
A piercing shriek jolted Luna's attention to another caricature of Rarity. The alicorn's eyes gleamed as she challenged the dream monster, "you're no true Rarity! Spike would never give you that fire ruby!" The white mare grinned a manic grin full of sharp teeth a dragon would be envious of, then held up a fire ruby in her magic. Luna's horn glowed, and a powerful beam of magic drove the creature through a wall, making its own magical field flicker and break. "Twilight! The gem!"
"it's... a lie..."
A purple hue shimmered to life around the fire ruby, stopping it just inches before it hit the ground and sprouted a crystal pony, or shattered. Twilight quickly maneuvered it into place in the lock, which clicked. The huge door opened into what looked like a corrupted version of the Canterlot throne room. The stained glass windows showed images of Spike saving the Crystal Heart, Spike dressed as his Ogres and Oubliettes character, Spike as Humbug beating up the Maneiac, Spike saving Applejack from timberwolves, and many more. The dual thrones of the two sisters had been cast aside near the doorway, and in their place was a massive pile of gold, ice cream, gems, comics, the Elements of Harmony, sets of dice, and even the Crystal Heart.
"I don't want that!"
On the ornate, gold-and-purple carpet leading to the treasure pile, Twilight saw Spike. She flew towards him, only to stop short when she realized who was on TOP of the treasure pile: Spike, being fawned over by Thorax, Ember, and a much more accurate-looking Rarity... with wings.
Twilight looked between the two of them; behind her, Luna barricaded the door against more Rarities and crystal ponies. "Spike? Who is... what's going on?"
The Spike on the floor turned and ran towards her. "Twilight! Don't listen to a word that guy is saying. None of it is true! I'm Spike. He's not me!"
Luna whipped her head around and galloped towards them, flapping her wings for speed. However, before she could get there, a blast of green flame shot from the strange Spike's mouth, striking the other Spike too fast for Twilight to even put up a shield.
The room darkened; both alicorns could feel an immense power gathering from the dragon's fury. He glared at the intruding ponies, eyes glowing gold.
There was a crash of thunder, and everything changed. The weather outside the hall grew dark and stormy. The scenes in the stained-glass windows altered, now with red backgrounds: changelings prostrated before Spike, crystal ponies prostrated before Spike, Applejack prostrated before Spike, the Power Ponies prostrated before Spike, the Princesses prostrated before Spike, and more of the same. Thorax and Ember hovered in front of where the hoard had been, huge, unnatural grins plastered on their faces with hearts in their eyes. And as for Spike...
A huge dragon loomed at the far end of the hallway. Every inch of what Twilight was sure were purple scales and a green crest was covered in layers of gold and gems. The creature held a long and broad sword in his mouth, his wings were enormous kite shields with Spike's face emblazoned on them as a crest, and dangling from his tail was the Rarity alicorn, trapped in a golden and diamond-encrusted cage but staring adoringly at the adorned dragon. Twilight felt a weight against her side, and turned to see that the Spike by her had fallen unconscious. She ignited her horn and blinked the two of them away from the amalgamation and the corruptions of the leaders of the dragons and of the changelings.
Luna stepped up, a look of pure determination on her muzzle. "Nightmare," she commanded, "and Tantabus." From her mane and her horn, Nightmare Moon materialized on her left, and the purple, starry dream construct flowed into existence on her right. The alicorn of dreams turned her head to address Twilight, and said, "keep him safe, Twilight Sparkle. I am counting on you. And more importantly, so is he." She crouched, spread her wings, and lit her horn; the two monsters of her own creation followed suit. Spike's shadow roared, and as one, he, Thorax, and Ember rushed forward to meet their opposition.
As magic and gems flew, Twilight concentrated on keeping a solid, purple shield up between the fight, and herself and Spike. This paid off a few times, when a diamond Luna chipped off of Spike's shadow skidded off its surface, or when a solid hit from the changeling-turned-bugbear sent Nightmare Moon careening back and using the shield to spring off of. When she felt she had the time, Twilight funneled some extra magic into Spike's body; it was a rudimentary healing spell, but Twilight hoped it would be enough.
At last, the final blow was struck: the Tantabus severed the shadow's tail with a blade of dreamstuff, cutting the fake Rarity off from the dragon, Luna struck a weak spot with a stunning spell, and Nightmare Moon used the opening to shove what is scientifically called "a boatload" of dark, destructive magic down the dragon's throat. In a flash of light, the scene had returned to where it was before. Spike stirred against Twilight's side as his shadow remained on top of the assorted hoard, the phony alicorn, changeling king, and dragon lord watching him in adulation. Twilight helped the purple dragon next to her to his feet, and they approached once more.
Spike's distorted voice echoed through the room.
Spike sighed and walked up to the pile. "Look... you're... you're not right, but I wasn't fair saying that I don't think that way sometimes. Living with and near a group of mares who save Equestria on, what, a weekly basis? would make anyone feel unappreciated." One dragon climbed the pile, while the other slid down it, sending gold coins and small rubies clinking down the slope. "A month or so ago, I finally realized how much being blinded by my fame and ego hurt other ponies, so I tried to make up for it by pretending not to have any. Just pushing down the thoughts of a reward for everything I do to help.
"It was making me miserable, I suppose, but I did such a good job of hiding it, even I didn't realize what I was doing. I'm sorry, I didn't accept you of first because I was terrified of what I might become - what I HAD become in the past - if I acknowledged your existence. I was so scared of another 'acting on behalf of Princess Twilight' or Greed Growth fiasco that I stopped letting myself feel deserving of anything not offered unprompted." Spike stuck out his hand. "I am Spike the Brave and Glorious; no matter how much I pretend in Ponyville that I don't have a statue in my name, that's just not the case. I saved the Crystal Heart, I delivered all those friendship reports to Twilight when Discord corrupted her, hay, I even DM for Discord. Nopony deserves EVERYTHING, not me, not Twilight, not even the Two Sisters, but I have to stop pretending that, every so often, I kind of like to picture it."
The other Spike took his hand and began to glow. There was a flash of gold, and the other Spike disappeared, leaving only the young dragon who had fainted through the battle. The hoard vanished, too, leaving Ember, Rarity (still an alicorn), and Thorax sitting at a round table with paper and dice in front of them, as well as an unoccupied DM screen. He turned to the two non-Rarity alicorns and smiled. "Thanks, Twilight, Luna. I don't know what would've happened if you two hadn't showed up."
Twilight gave him a bittersweet smile, tears threatening to leak from her eyes. "You're welcome, Spike. I'm sorry I didn't notice you felt this way. We'll have to talk more when you've woken up." She turned to Luna. "And, uh, Luna? Is this a common dream thing, or a special case for him being comatose?"
Luna nodded in acknowledgement of Spike's thanks, then replied to Twilight, "it is... uncommon. Most are not so dangerous or powerful, but I've learned my way around them, as you can see. Now come, we should leave Spike to his dream. If I trust what I glimpsed of those character sheets and campaign notes, you will not want to stick around and watch, either." With a spell, she summoned a door out of Spike's subconscious, and dragged a chronically-curious Twilight away from the table and back into wakefulness.
Author's Note
Okay, so I know that Shadows technically aren't really Demons, but work with me here. And this is sorta assuming a minor AU where Spike actually notices how much of a jerk he becomes whenever he gets a tiny bit of fame. It could happen literally anywhere after all those episodes.
Designing Spike's Shadow Self boss fight was a lot of fun! If I'd had the time to go through the fight itself, the shapeshifting Tantabus would take on Thorax, the merciless Nightmare would clash with Ember, and Luna would steadily wear away at the main body. The gold and gems protect him and make him bigger and stronger, his deeds giving him power, and his dove in the gilded cage, Rarity, would heal him with her love, preventing him from losing even without his armor, because he's fighting for his greatest treasure.
