Yoy, sorry to bring some more fire here, but I have to defend WH40K

What WW says is bull

They have like a dozen ways of doing exterminatus, ranging from the virus thing that does not kill everything ( d'huh, it did exist, in the veeeeeery old editions of 40

), to some things more efficent like plasma bombing fault lines and crust borders to trigger some natural disasters, to vaporating atmosphere with -don't remember what- bombs. And finally, there's that Chaos star killer ship. I skip a lof of them, like the geobomb, etc.
If I could find it back, I'd post that funny article about a guy who asked why the Imperium wouldn't tract large asteroids to execute Exterminatus, comparing costs
