Based on my best friend's empire on Stellaris.

Open ended intro - you can be anything you like.

Quick lore :
Long ago, Lyrians were destroyed by an AI that they created. However, after achieving it's goal, the AI was left without an objective to work towards, so it decided to recreate the Lyrian race. As a result, they have a bio-synthetic body.
After they started expanding to space, they quickly became the dominant power, and was elected the galactic custodian.
Now the galaxy is under attack by an unknown threat and Seeker Mei is tasked to enforce order in sector H3, the system where the threat had originated. She lands on H3-04, the planet where the user is living in.