Those bloody Khaak, I tell you. They're nasty intolerant bastards who should be shot. Oh, they are ? Great.
I know I've mentioned clusters before but while I've been hooning around I've seen some beauties. Check these:
Normally one Khaak is one little triangular segment, maybe 2 'blocks' of one of these clusters. The first two are huge, and suffice to say I did not get as close as the screenshots make it appear. Even with my 6 ships following me, I did not feel safe taking them on.
Little buggers like the one here are no hassle at all, there's at most 10 ships (one M3 and several M5s). That might give you an idea of why I don't like messing with them.
About the only GOOD thing is that when a cluster splits you get maybe 5 seconds where they're 'stunned' for lack of a better word, and you can usually time a missile hit so that the splatter effect gets many of the small ones.
That said it's still something not for the faint hearted if it goes wrong.
Historically game-wise nobody knows where the Khaak come from, they arrive, they kill, they leave. Nobody has communicated with them so they're very much an enigma.
The Xenon however are actually caused by people - apparently some terraforming droids were sent out into the galaxy at some stage .. and they became the Xenon, who are apparently self aware if not sentient. They don't communnicate either. Be nice if either one spoke gibberish at you, 'coz otherwise they seem very wooden. Scary but still wooden.