That power belongs to ME!
Flames of a sickening green pierce the clouds in the dark sky. Celestia folds her wings, allowing gravity to pull her out of danger. Far enough away she fans them open, catching herself back into midflight. Through the endless night, a ray of yellow light shines like a small sun, building from the tip of her horn. Aiming it at the fell-dragon, a cone of solar energy rips through the air, striking the skeletal beast in its side. A loud, angry roar is its answer, as the tendril wrapped maw stretch so that it can release another fireball. Again the princess avoids it, but it pummels into the city streets.
The night comes alive with fire, ponies run frantically out in the streets. Equestrian Fire Department rushes to the burning buildings, buckets of water saddled around them. As they start to put out the fire, a stream of emerald flames careen from above, incinerating three more houses nearby.
“Sister!” Celestia cries out. “We must stop him or innocent ponies will be in harm’s way.”
Luna joins her side, seemingly blending with the night, “He is after us, dear sister, perhaps we can lure him elsewhere.”
Black wraps about her horn as she shoots a beam of energy at the dragon, striking his skull against the cheekbone. Spike winces, but turns and lets out another furious roar. His emerald eyes find that the alicorn sisters have taken flight, becoming nothing more than twinkling stars in the blackened sky. Boned claws dig into the rock of the castle, pulling the dragon up out of the tower.
You flee from me? You flee from your subjects? Give back that power. It is mine. Mine. MINE!
Purple tendrils erupt from his spine, splitting into two arcs that fall on either side of his body. They twist and protrude, weaving and forming. Pulling himself out of the tower, the newly formed wings gust the wind underneath him, lifting him off the ground. The titanic dragon hovers off the ground just a couple feet. Another flap of his wings propels him higher as he gives chase after the princesses.
The sheer size allows him to catch up with only a few moments. Celestia looks back, and then quickly alerts her sister. Luna looks over her shoulder as well, gasping. Both sisters fly faster, trying to gain some ground. Behind them the air stirs, and tosses them about. A shadow loom over, cutting out the moon as a dragon claw comes down upon them, smashing them to the ground. They fall to the earth, being crushed between branches and the cold, unforgiving ground.
They manage to survive the impact, but are slow to get up. Celestia looks to her wing, find it twisted in a queer shape. Pain runs through it when she tries to straighten it out. When she looks to Luna, she finds that her sister has met the same fate.
“Can you still fly?” Celestia shouts.
“I might,” Luna winces, looking at her damaged wings, “But not for too long.”
Suddenly, the colossal dragon falls to the ground, causing it to quake.
There is nowhere for you to run. You will give me what is MINE!
Throwing his weight back, he comes forward and slams his claws against the ground. It causes a seismic quake that levels the forest. The sisters stagger, but remain hoofed. Spike lets flames loose onto the forest, setting the land ablaze in emerald fire. It singes the already fallen trees to cinders.
“He is relentless, sister,” Luna points out. “There must be a way of defeating him.”
Celestia looks over to the ferocious dragon snarling at him, “If he wants this power so much, then it is what he will get.”
“Sister?”
“Follow my lead…”
Celestia takes flight, and her sister chases after. Soaring trough the sky, they are bombarded by blasts of flames coming from their titanic enemy. Returning fire, the Princess of the Sun shoots beams, but they are blocked by the webbing of purple wings at his back. When he pulls his wing away to fire, he is unexpectedly hit by Luna’s spell, striking his mouth downwards to aim flames at his feet. The green flames snake across his body, making his hiss in pain, but he remains standing.
Suddenly, Celestia drops down low, flying straight on at him.
“Sister!” Luna shouts, “What are you doing?”
Celestia does not listen to her sister’s plea, as she seems to be focusing elsewhere. Her horn is aglow with its celestial light, even as she is being attacked by flames. Spiraling away from one fireball, she is nearly struck by another that singes her already pained wing. Wincing, she falls from the sky for a moment, but manages to stay aloft, drawing closer to the undead dragon. Just as he is about to charge another breath of fire, he sees a light breaking the horizon.
Night suddenly turns to day as the sun unexpectedly rises from over the plain. It is blindingly close, a colossal fireball only a few hundred feet from the lands of Equestria. Spike looks to Celestia, realizing she is the reason behind the sudden daylight.
“You want the power of the sun so badly,” Celestia shouts, her horn burning brightly. “Then take it!”
Throwing the sun, the ball of gas slams against the undead dragon. Spike roars angrily as he throws his claws up to intercept. Bones touch the sun, as he roars even louder, as he tries to force it back. It starts to singe his claws, turning them to dust. Claws turn to nothing, as the bones slowly start to dissolve. Even parts of his skull start to ebb into dust, startling with his upper jaw.
I will not be stopped. It belongs to ME! It is MINE! MINE! MINE! MINE!
Before the rest of his mouth his burned away, Spike opens his jaw and tries to bite down into the sun. The fangs are reduced to ash, but he still continues to bite down. Just before he is swallowed up by the sun, the great ball of fire explodes, shooting up dust that blinds the princess.
“Sister!” Luna cries, racing down to join her sister.
She hunts through the veil of smoke, until she spots a small shadow hovering above the ground. With tears of joy in her eyes, she joins her sister at her side.
“You did it,” Luna shouts in her equestrian voice.
Celestia smiles, “We did it sis—”
A suddenly huge shadow breaks through the smoke, and breaks the veil. The scorched skeletal jaws are opened wide ready to devour Celestia. But before they can consume the Princess of Light, her sister pushes her out of the way. Luna becomes a victim as she is devoured in one bite.
“LUNA!”
Spike appears motionless, his body covered in scorch marks. All of a sudden, his body is wrapped up in light and darkness. Celestia tries to get closer, but a shockwave sends her flying out of sight. The pained roars of the dragon slowly change, becoming fits of maddening laughter. And then, in one final explosion, he turns the land around in into a crater.
Standing in its center is a dragon of deep violet that it is nearly black. The wing on his left has dancing flames of the sun, while the other has the crystalized shards of moonlight. Opening his eyes, the pulse with power, a deep emerald gaze. Spike looks down at his claws, finding they are covered in scales again rather than bone.
“I am whole,” he smiles sweetly. “This is what has been meant for me all this time.”
He holds his claw aloft, as magic builds between his talons. Radiant light fires, illuminating the sky as it rockets into space.
“Thorn Eclipse has been reborn!” he shouts triumphantly. “And this is only the beginning. Equestria, for all the pain you have brought upon my family, I shall return it tenfold. You, Twilight Sparkle, shall feel the full force of my wrath. I will be the villain that finally takes her down.”