There are two things you need to understand about Benedict in order to really grasp how he does what he does. The first is that Flitwick was correct; he is a nephil (plural nephilim), which is defined for the purposes of this story in the Lexicon. The second is that he's a Catholic priest. Now, the exact nature of what it means to be a nephil will be explored throughout his story and another character appearing soon in the Narrator blog, and who Benedict's biological parents are will be revealed in story. So let's focus on the second for now.
Within the Roman Catholic Church, there is a belief that people undergo a number of specific ontological changes throughout their lives of faith; that is, the very essence of who they are is altered in some way through specific sacraments, such as baptism. These changes are more or less considered permanent, as they cannot be lost but the benefits of them may be sacrificed through mortal sin. There seems to be quite a lot wrapped up in this doctrine, and since I'm not Catholic I only have so much exposure to it anyway, so the focus here is on how this affects Benedict in terms of the story. If you are interested in the actual doctrine, this website seems to be helpful.
The belief relevant here is that the ordination into priesthood makes the priest a functionary of Christ. On a spiritual level, they are united with Christ in such a way that there can be times when it is Him acting or speaking or listening. Now, whether or not this is accurate within the world of Tall Tales is somewhat irrelevant. What matters is that, whatever it is that happened to the priest, it works. They administer sacraments, they preach powerful homilies, they cast out demons, they receive confession and are able to deliver a real sense of absolution, and so on. This state of priesthood cannot be lost, but the office of priest can, in fairly extreme cases. This means that Benedict, as a priest, will always be a priest as far as the spiritual nature goes, though if the Catholic church were to reject him for some reason he would no longer be allowed to act as a priest or administer sacraments or be paid by the church or any of that.
Now, in actual Catholic doctrine, this is about as far as this goes. There is no physical change to the priest, and there was no physical change to Benedict when he became a priest. What this means for Benedict, however, is that whatever benefits he has naturally by being a nephil, he gets to keep. Those are part of his biological reality and do not change through ordination. However, spiritually, he is not a nephil, but a priest. This means that, even if a being can detect his nephil biology, if they had enough information on his spiritual nature they would encounter something very different.
Within the rules of Tall Tales, this gives priests power that they are not believed to have in the real world, at least as far as I know. Mainly, this means that when dealing with spiritual entities, they are treated as holy beings. Their blood and spit and sweat function as holy water. This is because they are already consecrated, and their bodies are being used for divine purposes, which is basically all that needs to happen to create holy water. Their spirits are resistant to demonic attack (something that I think Catholics in general would agree on). They aren't immune to magic, at least in any way comparable to Matteson, but they are protected.
So, what you see from Benedict in the story is a combination of his biological nature and his ontological nature, based on taking what the Catholic church believes about priests and just applying that to a world that operates on slightly different rules. Maybe they work because this description is accurate, or maybe they work because enough people believe they work, but for the story all that matters is that they do, in fact, work.
I've been trying hard to keep up with daily writing prompts on my tumblr, and earlier this week I wrote a scene in which Jackie briefly explains the nature of magic to a character named Lori (that will be included in the story when we get to it; in fact, almost all the prompts are, so if you're interested in sneak peeks, you should be checking those out). She said:
"...it’s just a connection to the other world. There’s a spiritual backstage to reality, and changing things there can change them here. Sometimes it’s more efficient to make changes if you’re working with the spiritual side than with the physical side, and sometimes it isn’t. Magic just gives us the option."
Now, she isn't wrong. This is a functional definition for everything she does with it up until this point in the story. But readers who have been paying attention to "Benediction" may notice that it doesn't quite sound sufficient to what some characters there are doing. So how can we best understand magic as a broad concept in Tall Tales?
The short answer is that 'magic' is essentially any act that intentionally reaches across the divide between the physical and metaphysical realms. It doesn't much matter which side of that divide one is on; nor does it matter whether the effects manifest on the caster's side, the other side, or both. Magic in Tall Tales is capable of nearly anything, as long as a caster can find a way to do it and pay the price for it.
The longer explanation is that magic in Tall Tales is fundamentally about tracking down the intricate connections that exist between all things, which may or may not exist in the same realm as the things themselves. Magic will always, without exception, exploit the innate connections between things; sometimes by manipulating the connection, sometimes by interrupting it, and even by making new connections.
An example. Aaboukingon has an innate connection to the Ohio River. He isn't the only spirit that does, and there are several names he can be accurately called, but that connection exists and it is strong. The problem, aside from the overt racism of some of the characters, in "Land of Goshen" is that this connection is being severed by Aaboukingon drawing distant from his nature and role as a river spirit. By damaging the connection, both Aaboukingon and the river suffer.
Connections can be ranked as follows:
Humans have an innate connection between their physical and metaphysical selves, and the degree to which one is in tune with the other is called the Ontological Gap. A smaller gap means that there is less room for the connection to be accessed and manipulated. A gap that is functionally closed, such as the case with Warlocks and Anchors, prevent access to their ontological connection entirely; this means that magic which relies on that connection will not work. Such magic includes possession (in which a being inserts themselves into the gap and effectively overrides the connection) and mind control (in which a being implants information into the connection that the physical self reads as coming from the metaphysical self). Humans with a smaller gap, except Anchors, are therefore slightly more shielded from invasive magic and also find it easier to perform magic as they have greater access to their metaphysical selves. A full explanation of this concept will have to wait until a later post.
What is this?
Worldbuilding Wednesdays is a real-world blog, written by Tim McLaughlin, that gives a little peek behind the curtain of Tall Tales. That includes the process of creating the story and world, influences, world rules, and even the occasional story.