It DOES work for its intended purpose: stealthy slow kill for billions of NPCs, along with repopulation control. They're just warming up, they've neutralized the sheep, now they'll be up against the wolves in the next wave of global assualt, around 2024 I'm guessing. They'll strike ruthlessly, they know once the box is opened the masses of pandora will be not only awake but biblically vicious against their demon horde.