Nwyf

The diffuse metaphysical substrate of arcane magic, which passes through nearly all matter.

Penetration

Nwyf has the penetrative power of neutrinos, with the exception of very specific materials such as iron and ferrous materials. These do not shield it completely, but they can shape its flow, in a kind of magnetic deflection.

Behavior

Nwyf is "squirrelly". Almost like a creature with intelligence, it weaves its way in through imperfections. It is not magnetism, but magnetism is a good analogue for much of its behavior.