Re: Filter
It's been floated before that we're something akin to Tulpas. Manifestations of collective will but it is insufficient to argue that just because the majority of people do not believe us or anything like us to be real that we might not be.
Anything is a possibility, it becomes a matter of how to provide evidence to support or refute it.
I suppose we could also all be from mostly similar parallel dimensions and that we actually do disappear and reappear with knowledge of this place such that two people who might feel they know one another know rather a very similar person from a world that is only minutely different. A world where blue is perceived as cyan, or one person missed an elevator they might otherwise have caught.
I had a young protegee who found herself in a similar situation. In truth, I found myself in one. Magic as I have learnt it is an intrinsic ability honed through meditation, willpower, and a series of complex deals with extraplanar entities. Much is done with the Ethereal Plane.
Both Miss Kane with her Du'at and I with the Ethereal Plane have been able to access a version through meditation and some spellcraft. I would not be suprised if your Fade or something approximating it could not be similarly found just beneath the surface.