A shimmering golden light surrounded them, and as it dissipated, the three ponies found themselves in a massive stone temple, instead of the private chambers they expected.
“Oh, it has been eons,” Celestia said in a tone of wonder as she looked around. “The fortress!”
Tempest, a unicorn with a dark purple coat and a broken horn, looked around with a faint air of amusement, her armor giving her the appearance of a pony turned tank.
“I expected to be attacked immediately. You said Khorne is the god of blood and combat?”
“Among other things,” Celestia agreed, as a shimmering golden light started collecting around her, making her coat glow.
“Um… Celly?” Cadance, a pink alicorn who had once been Celestia’s student, asked as she pointed at the golden particles.
“Technically I am at the source of my power right now,” Celestia said happily. “This is the Chaos Fortress, the first world I ever helped create.”
A hissing hoarse voice came from the shadows, startling Cadance and Tempest.
“Ssssister…. You return, after sssso long.”
“Tzeentch!” Celestia said, sounding for all the world as though she was overjoyed. “My brother, where are you, what body do you have this time?”
A small shape stirred from behind a pillar, and strode out into the open. A human woman in a cloak which shifted slowly between colors and textures. She looked like she was in pain, tattered greasy black hair stuck to her cheeks.
“It’s…. Sssister, now.”
“Well, sister, you clearly are in some discomfort,” Celestia said, walking forward and lighting her horn, pulling back Tzeentch’s hood and tending to her hair.
The woman winced, her warped multifaceted eyes focusing first on Celestia and then on the other two ponies once she realized Celestia would not stop using her magic to clean her hair and tie it back.
“How am I unsurprised that you would make your race so saccharine. These are your warriors to confront Khorne? Why not bring your other shards with you?”
“Because if Nurgle decides to take revenge for my past actions, and destroys me, my remaining shards could reconstitute me, or at least lead my ponies,” Celestia shrugged.
Cadance and Tempest shared a glance, distinctly aware that if Celestia was destroyed, they had no way home. But they had signed up for a truly dangerous mission. Maybe they should have asked more questions.
“Nurgle is not so brave,” Tzeench laughed, her shrill voice echoing in the massive hall. “I’m sure that he will wait until you’ve tried and failed to stop the war, to attack you.”
Something in Celestia’s eyes shifted, her expression growing cold like a mask before a burst of magic surged out from her and pinned Tzeench to the floor. The human-looking woman gasped in pain and shock, squirming under Celestia’s grasp.
The sounds of a horrible roiling storm began in the distance, howling wind outside of the fortress, cracks of thunder reverberating through the stone walls.
“Do not Speak Lies into my Truth,” Celestia said calmly as Cadance and Tempest approached nervously.
“I’m sorry! I’m sorry! I do not Speak them! I unspeak them! You Will Stop The War!” Tzeench said frantically.
Finally, Celestia released the squirming woman, and allowed her to stand.
“We had an agreement, back when the world was new,” Tzeench gasped, holding her throat. “I wish to renew it.”
“You do not include me in your plans, and I do not bring my righteousness and control to bear against you,” Celestia said simply.
“I agree,” Tzeench said, and then in a swirl of multicolored cloak, she was gone.
“We shall not bow to thee, oh glittering star! Fie upon thy name and symbol, but a mockery unto harmony!” Princess Luna roared across the great hall, standing between the two shattered thrones of equestria, black wisps of magic sliding over her body like beguiling fingers.
“Thy grasp of harmony so firm this night, sister mine?!” Celestia shouted in reply, flames flickering across her coat, illuminating the floor and walls nearest to her. “Oh pray tell then, ever-wise, we take these shapes, we take upon us this bastard culture, and for what? No reward to be given? Thine own chambers we shall note, gilded in silks and silver!”
“Oh, the price of silver to be bartered against thy sheafs of gold leaf, please, spare us thine vainglorious simpering, sister!” Luna replied, her laugh half a cackle.
“Even now, a lie to thine own ears, how can it not be?” Celestia insisted. “Sister, itself, a falsehood! We are one, and evermore shall be, no matter our quarrel! My own spirit given fle--”
A spear, decorative and draped in crimson tassels, plunged through Celestia’s throat to definitively cut off her words.
“Sister,” Luna said, scowling. “Be sister mine, or be no more, wraith of Pride.”
The spear melted, and burned, and fell away as magic reformed shattered flash, Celestia’s pale red eyes fixed on Luna’s teal, the rage in them beyond measure.
“Why…. dost thou… insist…. on falsifying history?” Celestia choked out through blood filled lungs.
Luna stepped down from the thrones, slowly.
“Be sister mine, or be no more,” she said simply a second time.
The blast of heat which burned through the ceiling and destroyed the floor shattered every window in the building at once, every tapestry charring and curling with delicate flames as the light faded, revealing Luna in a sphere of protective darkness, smoking.
“Then a sister I shall find in others,” Luna said bitterly, as the shadows around them deepened, and Celestia felt fear for the first time in eons.
The tendrils grasped at Celestia, and scorched her like no fire ever could.
“Pray caution now, Darkness,” Celestia gasped. “This spar is not with thine troops, and our magicks tear at souls!”
“A shame,” Luna said coldly. “Thy soul would have been useful unmoored.”
A blast of sunlight roared down on them again, this time giving Celestia enough grace to leap and soar into the sky, as the moon itself began chasing the sun, intent on blotting it out.
“What hast thou passions seized upon so firmly that this is thine answer?!” Celestia asked as she was chased.
“Thou shalt lord over this race, this world, half tyrant, half mother, and thy abuse shall not stay silent forever!” Luna screamed. “We cannot remain distinct and godly, in amongst beings more harmonious than we!”
A lance of black sliced through Celestia’s leg, which Celestia responded to in kind, an explosion of force battering Luna and possibly hurting her, but Celestia was not ready for Luna to physically slam into her, knocking her out of the sky and bombarding her with dozens of attacks.
Celestia hit the floor of the great hall, cracking the stone beneath. But as she stood to confront Luna again, the moon obscuring the sun and leaving her plunged into darkness, cut off from her source of power, she saw a glimmer of light from under her hooves.
A chamber underneath the throne room floor, which Luna had built with Celestia’s blessing. A chamber to hold Luna’s pride and joy.
The Elements of Harmony, three made by Luna, three made by Celestia, which they had grown carefully from the harmony of the race they had built together. The weapon they had used to defeat Discord.
She realized that Luna was right, in the same moment that Luna gave up on harmony, ever being the answer to life’s problems again. Tears poured down Celestia, and she gave up her past. She was no god, she was just a very old pony, who was very tired, and had been so very wrong.
She unearthed the Elements from the rubble of the throne room they had built together, and she turned her eyes to the fractured sky, heart set in stone.