Dark Walkers

"Some o' the armsmen have to fight the shadow. Fightin' another man? That isn't hard, though regrettable, as the scholars acknowledge numerous threats already existing prior to fights between people. The shadowfaen however, seems to have a draining effect on the armsman's soul, and those injured by weapons wielded by the forces of Duinn have the potential to turn inward, and thus to the dark." Traveling Scholar from the University of Aubergeon.
The effects of Faen magic on humans can be varied. None however, is more sinister or terrifying than the shadowfaen. Soldiers and knights who protect their kingdom against the shadowfaen have mentioned hearing whispered voices as the creatures approached. Some, especially those who were injured in the melee, reported hearing these voices after the conflict, urging them to do violence and spread chaos, even to those they love. Often, these individuals commit suicide, driven mad by the constant voices they claim to hear. Some individuals become reclusive, eschewing civilization and leaving cities behind, retreating to the wilds beyond the Hearthsteads. Occasionally these troubled individuals find themselves joining bandit groups, or often killed by the very wilds within which they sought solace. Some however, become enamored to the shadow, and grow in power and potential for wickedness. The worst of these are referred to as Dark Walkers. 
A human under the influence of shadow will become sallow and pale, appearing sickly and gaunt. Hair will turn gray and fall out in clumps, skin, regardless of lineage, will lighten and bruise easily. Eyes will become bloodshot and finally darken to black orbs that have no pupils. As the eyes darken the need for light becomes less and less, until the dark knight can see during night as if it were midday. However with this darkening of their eyes, they begin to experience a gradual light sensitivity, until being out during the day without some sort of protective covering becomes too painful to bear. While their bodies appear to waste away slightly, their actual physical strength remains, until the these individuals are indistinguishable from the undead. No one has ever recorded an individual returning from the influence of the shadow, though it is not known whether this is a possibility. 
In battle, these individuals retain much of the skill they once had, though as time goes on, wounds appear to affect them less and less. These are however, still living beings and they can bleed out and be killed in the same manner as regular humans (though the similarity between them and Grim Walkers leads many to believe that their living stage is simply another step on the gradual transformation to the undead). As they transition, their blood becomes darker and darker, until at the end, they bleed a vicous black fluid that clots almost instantly, with the only significant bleeding coming from slashed arteries. 
Until the very end of their transformation, the Dark Walkers can converse with unafflicted humans, occasionally trading and seeking information about current events. Though they can be conversed with, they are sullen and quick to anger. As they transform, they begin to see humans as encroaching on "their land" and are more likely to attack on sight.