Ciencia
The universe is vast and disparate. Every world is uniquely different, yet somehow they share common artifacts. Grandiose temples and monuments containing ancient technology exist simultaneously and inexplicably across all worlds. An untouched universe, selfishly meddled with by a race of explorers, The Oort. Now extinct, all that remains is their legacy.
By harnessing artifacts left behind, your people have created Portals between worlds. Long after the time of The Oort, all species of the universe live, build, trade and fight together. The universe is yours to explore.