I find "evil empires" not all that interesting to write. They're good if you just need an antagonist, but they tend to not have much interiority, you know? At best you get squabbling nobles and I find these uninteresting.

But an evil federation, which has a parliament, as well as reasonably free and mostly fair elections, but also the most Fucked Vibes you can possibly imagine? Now there's all sorts of story hooks in there