@alacaelum I don't think that's how it works. It's way too vague, from the way you explain it, you're assuming it essentially comes out of nowhere. Remember, Seth is a target because he can control fantasia with his bare hands. He is the only exception, even among infected. (Would include Myr, but nobody knows Myr is a pixie except for Seth)
Chapter 26, Grimm mentions there is no trace of fantasia being used.
Chapter 56, Diabal explains the seperation between infected and the Inquisition. The Inquisition relies on their magical tools.
I think these two chapters imply more towards the idea that the Inquisition managed some type of technology to create different miracles. Heck, they created a vacuum that sucks in all the fantasia in the surrounding area up to several kilometers. It has to be some kind of device, because it's mentioned in the last page of chapter 18, at the bottom, it states that they're called "The miracle workers" because of the skill they acquire after initiation. So it's clearly something applied and not developed, or at least something is applied to help develop it, or else that would just straight up make any normal human potentially stronger than any sorcerer, especially since they don't require fantasia.