Not to be a snoop or anything but there is a very easy way to get around Horned Skin of the Fir Domnann's Champion and it can be taken from your own words. You said that no man was willing to strike Ferdiad but this could be interpreted as the fact that a woman could strike without fear of damage being returned to her and anybody with Divinity could do the same. Taking the word 'man' as referring to humans would mean any sort of Divinity would reduce the damage or negate it completely.