This is the power of Godhood and the Field: Godhood materializes the rules, while the Field extends the power of those rules. By wielding Godhood to grasp the rules, one can display their formidable might in the form of the Field.
Yet this was merely a Demigod Avatar, not even a potent one at that. The force of its Field was limited. Had a True God taken direct action, Lin Xiao, even as a Divine Being, would have been unable to withstand the power of the Field and would have been drained of all Divine Blood on the spot, becoming a dried husk.
Therefore, when Lin Xiao unleashed more than five million Power of Faith in one breath, the overwhelming Divine Power instantaneously blasted open the Blood Realm affecting him. His form flashed as he burst forth from the heavy blood waves.
