I am not sure what paint you are using....or if its the quality of the primer.
But either you are using TEXTURED paint, or the figure is rough as all hell.
I used to have this mini by ral partha and the death knights of kryn box set, but I do not remember Soth being this harsh on detail.
It looks like he was painted with chalk, I am sure its not your skill,rather the paint you are using.