You know, I built these things for d20 at one point for a realm in ravenloft (a horror setting for D&D). The way I figured it, ravenloft was probably a lot bigger than was mentioned in the book, and probably had a lot of realms that broke away from the midevil/victorian referance.
So I decided to add in colony XX-### as a horror realm that the characters acciented across. As the master of the domain, I placed a not-so-standard exec from "The Company". He was actually contolling the aliens subconsciously. From there they also ran into the broken realm of No Man's Land, ruled by the Joker of DC comics. Finally, they limped into Purity city. Here, those with mutant powers were hunted to extintion by sentinals (think marvel) with the actual lord not being a political leader, but a mad AI manufacturing the sentinals.
Man, that was a wierd game. The players thought it was intersting though....
The Fool