The turret was simply the first piece of the puzzle, and when Shani placed it down, she did not have it shoot immediately. After all, the sentry gun needed to detect enemies to begin shooting first and it was too difficult to program the Grey Rot as an enemy.
While the sentry gun was transformed and augmented by a Divine Law, allowing it to hit even ethereal things, the Law also followed the rules of modern warfare, in other words, kinetic bullets were unable to strike fog.
However, Shani had an alternative for that!
Using her will, she connected to the hind chopper above that had the shredding high caliber gatling gun attached, angling the chopper in a way that gave her full view of the battlefield.
