what IS the veil, exactly?

[Minyatur]

To go black to my notion of psychic filter. The veil is a complex thought form, it does not simply blind you but also literally diverts your awareness from certain things if it lacks will to pierce through the force. It disallows you to see certain things (or have certain thoughts) unless you truly focus willpower into it, makes you forget things or not think again about them.

Astrology is the study of the imprint of the moment of birth upon the veil (imprint of the interconnection with all things in the great cosmic clockwork studied locally).

I think there's quite a fair share of programmable layers to the veil also. To sub-design facets of it to suit your plan.