Contrary to Ian Gorlick, I think the Uz are afraid of Subere. Any rational
being is. Darkness has an aspect which is unknown and unknowable,
unnameable and unspeakable, the darkness where light can never go, the
oldest dark, black beyond black. "Uz know; I experienced it." Fear it.
All the darkness gods participate in this aspect to some degree, and there
is a frightening aspect to Xiola Umbar, even. Certainly the story from the
new Trollpak is scary enough.
The spell I object to, because it seems so obviously designed for monsters
to use against PC's, is Kyger Litor's Blinding.