Styon-Touched are those who don't have any relationship with a deity in a nation that worships the Ramaldian Sphere. They are called this because the worshippers of the sphere believe that they are protected by the deity of atheists, Styon the Void Child, which in a way is true. Only by being considered Styon-Touched is that unfaithful or godless Sinferi may survive into adulthood.
In general most of the Styon-Touched are those that don't believe in the power or existence of deities, but live in society that does, the Apatheists. However there are other stances that grant them enough power to be classes in their own right: