My new ideas include either a empire of humans (and alien minorities) infected by an alien space brain parasite virus that are spreading it to create a hivemind to pacify the galaxy,

an empire of aliens that have become culturally human after so long assimilating and now consider themselves successors which are rebuilding the galactic empire

or a totalitarian human state much like Monkeypants that competes on which hates aliens more.

Which do you like more?