The description of the spell states that a unit hexed by this spell treats all terrain (except impassable)as dangerous terrain - does this include open terrain?
While at first I thought this is one of those RAW issues, but the description of the spell says that the target is being assailed by spectral claws rather that the terrain itself.
Not to mention impassable terrain is specifically excluded but not open terrain - just an oversight on GWs part? (Wouldnt be the first time)