I heard this idea mentioned in another thread, and it caught my interest. These are some initial variables to roll from, and I'm open to suggestions on what other information is needed, or what other background may be helpful.
Process:
1) Size of the Xenos Empire
2) # of planets they control per star system
3) The Empire's outlook on the Koronus Expanse
4) Their Allies or trade partners
5) What the Xenos look like
6) How advanced their technology base is
7) What their ultimate goals are
8) The most important group they've encountered during their history
9) What type of void ships they operate