Prologue - Divergence
Thrust into both royalty and hailed pantheon they were thrown; saviors of all hoofed, horned, and winged kind, the chaos of Discord quelled by their combined harmonies. Despite all their power and immortality, they knew it wise to seek counsel, for what would two rulers be without gaining knowledge to better protect Equestria?
To the highest peaks of the Frozen North they ventured, discovering their sought quarry hidden away within a small, molding cabin cast in the great mountain's shadow. A whipping blizzard raged outside as they awaited by the flickering glow of a lit hearth, feverish howling pounding away at the shack's walls.
The rags-clad figure of the hermit stepped forth once preparations were finished, casting a handful of sparkling powder into the fire's crackle, its color changing from a vibrant spectrum of reds and oranges to a cold white, spilling out and growing tall enough the edges of the flames licked the ceiling of the hut without burning it.
All warmth left the abode in that instance, the once cornered shadows emboldened to creep out longer, darker. The two princesses shivered, visible breath on their lips as they gazed onward, startled by this display.
Within this marrow-pale blaze, they witnessed visages of themselves, all passing by so fast it was almost a blur, too much information to process at once. Day by day, scene by scene, plucked portions of their lives that had occurred, or were yet to transpire.
Some were moments of weakness, others of triumph. There were ponies they knew, or didn't know at all. They stared, mesmerized at these dreamlike interactions.
"What will become of us, oracle?" Asked the eldest, failing to hide the worry in her voice as she tried to discern this barrage of knowledge, eyes flitting over to her sister, gauging her reactions.
"We have been told your prophecies all come true in some manner," commented the youngest. "Please, we must know, no matter what it may be." She tried to appear calm, maintaining a stifled demeanor.
"You will rule. Your land will flourish. Your people will be happy, for a time. Too happy." Her voice grated louder than the storm. "From this prosperity, bickering will arise, jealousy seething into anger, anger boiling into a darkened heart."
"Corruption shall overtake thee, a magic most foul." she pointed a long, pointed nail at the youngest, who stilled at the accusation, her ears and tail lowering shamefully, while the eldest bristled.
The sisters shared a glance, the images within the hearth slowing down almost mockingly to the two of them arguing. Shouting, demeaning insults, barely withheld threats of violence in their body language.
Then, the youngest transforming into a form of pure midnight, all of her most dreaded aspects magnified to a malicious degree. They clashed through both land and sky, their battle taking them across Equestria, destroying their home in the process.
It ended with a brilliant light, six chromatic beams piercing the veil of oily blackness and banishing the Night Mare forevermore.
"All brought on by the youngest demanding she be treated as an equal worthy of praise," the crone turned her lidded head to that of the moon. "All because the eldest neglected her sibling in her self-righteous stupor." The hooded face of judgment fell upon the sun.
The fire sank back gradually, heat returning as it did so. Tears were budding in the eyes of both alicorns as they stewed with this revelation settling upon them.
"Do with this what you will," the sage said, extending an outstretched palm to both of them. "My services do not come without a price. Our agreed-upon payment. Now."
Barely snapping back to the present, Celestia nodded shakily, her horn glowing with all the splendor of dawn. Joining her, Luna's own horn surrounded itself in a night's worth of arcane essence.
The hag grinned wide, accepting their tokens all too eagerly, exchanged for a glimpse of what the future held, lest they changed their ways.
And change they did, restructuring how Equestria operated as a kingdom within weeks of their visit. Rather than a dual-rulership over its entirety, they agreed to separate their territory into two equal domains, one led by the day's light, the other by the night's shroud.
The noble families and descendants of the settling leaders were most unpleased with this change in status quo, but who were they to disagree with their princesses? Those who disparaged the idea either fell in line or were exiled to neighboring countries.
These divided lands would come to be known as The Sun Court and The Moon Court, while still being part of Equestria proper, not wishing to disrespect the name founded by the three tribes.
A 'friendly' competition was formed to decide who would keep their home of Canterlot, as it was a central point of power that would define the dividing line between the realms. Champions from both sides partook in a tournament that lasted three days and three nights, with the reigning victor handing Celestia the mountain-city, as well as the southern portion of the country.
Luna, and those who followed her, would establish the Moon Court's capital of Lunar Bay in the north, resting underneath the protection of the Crystal Mountains.
Both societies would co-exist and develop alongside another for a millennia; while the catastrophe of their fated conflict had been averted, a deeper, more familial problem arose. The sisters drifted apart, the unity that initially bound them unraveling.
They saw each other on occasion during festivious events or times of crisis where they were forced to band together for intervention, but otherwise, time and distance separated them. The Elements of Harmony were sealed away, as less and less use for them were required, year by year, century by century.
It wasn't until a thousand years later did Princess Luna realize she was lonely. Life had become a flash of the vaguest sense of passage, lost to her in a deluge of duty. She had advisors, loyal guards, those that relished in her night, but still she knew she felt … empty.
She truly hoped that her sister, living on that distant mountain so far away, felt the same.