The Leaves From The Vine
Billions of years ago (So many billions as to be before the birth of our universe) There were the Progenitors. They lived deep in a bright, perfect universe, in perfect harmony with each other and their surroundings. There were no wars, no conflicts, and no suffering. This existence suited them just fine for such a long time, that measuring it would be pointless. The Progenitors grew complacent and lazy, as having the infinite energy of their universe at one's very fingertips makes living quite easy. Even the most simple of Progenitors could create vast armies and colossal starships with the snap of their fingers.
One day, a driven and intelligent Progenitor named R'eit decided to create artifacts of immense power, as a personal project. Many great machines were created, not all of them peaceful. R'eit's fellows disagreed with his irresponsible experimentation, and in doing so incited the first conflict. Many of R'eit's kin became nervous with his experiments, but by the time someone tried to take action upon him, it was too late.
one of R'eit's experiments failed. A blight swept the universe, turning it into a vast, dark abyss. Progenitors all across the universe were turned to nothingness. R'eit only saw one escape; punch a hole into another universe. In a last stand, R'eit created a rift between universes and catapulted his people into a newborn cosmos. Our cosmos.
Many billions of years passed and R'eit began to experiment in a new galaxy, in a new universe. He created one base species, and planted them on life sustaining planets, watching them evolve in different environments. His experimentation and fun were short lived, however, as his kin eventually caught up to him. They assaulted his vessel, and exiled him into deep space. After disposing of the troublemaker, they created hundreds of vaults to hold his creations. on one of his experimental worlds, they built a gargantuan fortress, to hold the entire species. Deep in space, however, R'eit was at work. He created a species ending relic, designed to wipe the progenitors from existence. Believing that his kind had dodged their natural end, he activated the last of his creations.
The progenitors were wiped from the galaxy, but their effect is still apparent billions of years later. Ancient temples, dead armies, and powerful relics still dot the galaxy. The species created by R'ait have grown to become powerful interstellar societies, mingling with the species that evolved naturally. The ancient fortress is now the center of the biggest city ever built. Most importantly, a faint sliver of the cosmic power weilded by the Progenitors has trickled down to modern life. These arcane few can manipulate the very fabric of the universe, in a way that can best be described as "magic". Most people assume that things have always been this way, but a select few feel that there's more. These relic hunters scour the galaxy looking for evidence of those who came before. They know that our tiny sliver of the galaxy is just a leaf on a cosmic vine.