Initiate

The term Initiate is a joint description for all humans that are excluded from the Censor's Veil, which allows them to witness the true state of the Reality. Their nature is a double-edged sword, for while they are capable of fighting against the things that go bump in the night, they are also much more likely to gain the attention of said things.
Initiates are recruited from Non-Initiates through a proper ritual. Any Initiate can, at any time, grab a Non-Initiate and describe to him the world behind the Veil. During the Initiation, the Veil will be temporarily lifted, allowing the Initiate to use various props (or supernatural entities roaming around) to make the Non-Initiate understand that they are saying the truth. If they truly believe in what was said and consciously decide to get Initiated, they will.
If the initiator changes his mind or if the Non-Initiate refuses, the procedure will be terminated, and the Non-Initiated's memories of it will vanish from their mind. In the end, many Initiates are divided as to whether agreeing was a good or bad idea.

Perception

Purpose

Initiates, as a whole, appear to be a form of Mankind's self-defence mechanism, perhaps connected to the Censor's Veil. In more ways than one. Unlike normal people, the Veil doesn't keep them unaware. This means that they are capable of holding various threats at bay if some only temporarily.
In other words, Veil keeps people unaware... but it's the Initiates who are supposed to make sure that there are people left to be unaware. Of course, that's if you accept the theory that there is a point to the Censor's Veil. Otherwise, Initiates might simply be a bit more interesting toys for the Powers.

Demographics

The number of Initiates per population varies greatly. It is generally estimated that only about one per one hundred people are Initiates. However, there are certain supernatural-heavy areas where the percentage of Initiates might approach 100%. And then, some places are Initiate-free (if only because something has just eaten them all). In short, it's hard to gauge this.

Operations

Tools

Becoming an Initiate allows you to perceive and use every single magical tool, grimoire and artefact out there. Many newly Initiated end up discovering that one of the books on their shelves was a grimoire all along. Or that old clock they got from grandpa is an artefact.

Dangers & Hazards

Initiates have one major occupational hazard. They gather attention. Of both the Powers and all the lesser supernatural entities. They are, simply speaking, much more interesting (to the Powers) and a potential threat (to the latter). As a result, when something nasty moves in somewhere, Initiates tend to be the chief among its victims.
Of course, most supernaturals will gladly kill random people for kicks or food, however, this will be more of an afterthought. Their conscious actions will be focused on Initiates, who are much more likely to successfully strike back.