Hmm, I'd like a few opinions on this.

Between these, which do you think is best for my marauding space barbarian/swarm-ish guys?

space bugs(could be filed under rogue bio-weapon as well or a somewhat natural thing) , Crusading Cyborg cultists or rogue bio-engineered weapons(could be filed under space bugs or could be anything else, like modified cloned soldiers and other such things)