In the moment he appeared, it was also the moment when the Thunderstrike Main Cannon struck. The surging lightning fully engulfed the incarnation of Plunderer Kallargos, along with his angry bellow of "No".
This manner of death was unacceptable to him; as a God Incarnation, he could only die by the hand of another deity, how could he possibly die at the hands of a Treant that wasn't even Legendary Level? If word got out, where could he put his old face?
But in the Material Plane, everything must follow the laws of the Material Plane, an attack is an attack, it does not differentiate whether it's from mortals or a God Incarnation, as long as it hits, it will cause damage, and if it's a counteracting force, it will cause counteracting damage. Not to mention a God Incarnation, even a God Saint could not avoid it.
