you may have seen this if you're on my ao3

The elf stared coldly at the demon... his brother as it turned out. The reincarnation of a past friend-turned-enemy. Xornoth stared back equally as coldly, clearly remembering the same.

"We meet again," the demon, the embodiment of darkness, snarled. "And this time I shall defeat you, Aoer ."

A fierce, hot, light fire spread through the elf's skin, his veins, his very core; the energy of destiny, of power, of good. His mouth opened of its own accord, speaking words he didn't know. "Indeed, Exor, let us finish this."

The demon lunged at him and the elf instinctively ducked beneath his dark form, then twirled to face him, cloak whipping about on his back. The demon had sprouted dark, gnarled antlers and shadowy wings and the elf knew where this was going.

His own majestic golden wings unfurled and he shot up into the sky, in perfect sync with his opponent, his opposite, his eternal enemy. He dove sideways and they fell into a perfect rhythm; slash-duck-stab-block, clashing in a quick, graceful dance, centuries of anger and spite apparent behind a facade of smooth, elegant movements.

Aoer's reincarnation drifted higher and higher, gravitating towards the bright sun, the source of light in the world; light, his element, the representation of good, just as he himself was.

Ever paralleling his enemy, Exor's champion gradually tried to descend, to retreat as he always did to the safety of the shadows, his strongest ally, his tool for spreading the evil he represented.

"Give up," he hissed, his voice and the familiar deep growl of Exor intermixing in a dark harmony.

"Never," The elf felt Aeor's own high, lively song joining him, entwining in a perfect, symphonous balance.

"Darkness shall always prevail," Exor snarled pridefully. Pride had always been his weakness. He never did learn, not over the many eons they'd battled, not through the thousands of forms they'd taken, the hundreds of worlds they'd inhabited. He never changed, never adapted. And that was his downfall.

"You know that's a lie, brother," Aeor replied, calm and unafraid, never faltering, never giving up, never growing too upset. Aeor was the spirit of light and joy, happiness and prosperity. It was not in his nature to be angry.

Had any been watching from below, it would have seemed that the entire sky lit up in flashes of light and dark, perfectly balanced, just as yin and yang were. Always in conflict, but never could either one win, only gain the advantage for a time. Always did darkness return to the world, and always did the light drive it out.

And with one final silent supernova of light and dark, flashing and dancing together in the sky, the world was changed.

Two figures appeared in the center of the blast, each going limp and plummeting from the sky, together as they always were. Perfectly in sync in life and death, light and dark.

Two identical thuds rang out at once, combining into a louder sound.

When the others found the scene, they found two bodies.

Neither dead, but neither fully alive either, meeting at the boundary between the planes of life and death just as they met at dusk and dawn at the melding of their realms.

One blue figure, one red, opposites as always.

One elf and one mortal, lives balanced perfectly.

One known for his love, the other for his vague morals.

Both constantly drifting too close to the line between chaos and good, one always on either side, always drawn towards one another.

Scott and Sausage, opposites always, friends despite their fates, bound together by destiny.

Aeor and Exor, opposites, brothers, enemies, immortals.

Ever present, reborn throughout history, eternally rivals.

Today was a victory for the light. Perhaps next time the darkness would prevail, and that was how it was. They would die, but they would return, just like the night and the day.

They always did.