I'd feel bad about completely erasing any of the potentially peaceful factions (not Cravers, not Horatio cause he's a fascist and called me fat), because I'm not trying to rp as evil conquerors of the galaxy.
I keep culling my sleepers on every system so I know that's not it... maybe. I also know it's not the Umbral Choir (too far, busy w/ Cravers, in my Alliance) or the Sophons (too far, busy with war with a three party alliance, neutral towards me). Process of elimination says Nakalim or Horatio because of their hostility towards me and our galactic geographies. I really don't want to annihilate the Nakalim, what else can I do?