7
For untold eons, the ancient race known as the Reapers would unleash a regular cycle of mass extinctions every 50000 years. It was the Reapers that created the Citadel and the mass relay as key components to their cycle of purges. And when the Reapers came to initiate their latest cycle, the various races of the galaxy would be forced into a desperate galactic struggle against their approaching doom.
