Huxley ensures the endless food from the sacred tree hasn't absorbed the 4th Layer's curse (which causes intense full-body pain and bleeding from every orifice). Since the tribe feeds wicked human souls to the Abyss as payment, a taster must ensure that the negative karma, malice, or residual spiritual corruption from those wicked souls hasn't drifted into the sacred tree's root system or the tribe’s direct food supply. He does not use the tribes dark powers