"Then somehow the Null must have been extremely efficient when it came to killing them all off. And, presumably, that it was easier to do that than to kill the gods directly. So why don't they attack more often? Are the Null limited in number, themselves?"

The impression she had gotten was that they were a fairly large collective. Surely, slaughtering everyone in this city ought to be a simple task based on sheer numbers alone. They would win in a war of attrition, wouldn't they?