Nighttime. Dreamtime. The hours when the demons of the mind could take hold, their cold gras firm until morning. The hours when the human soul abandoned its struggle against the maddness of this world, and the dark things that lurked in the corners of the human heart could take form at last. - Crown of Shadows by C.S. Friedman
He is a grim reaper, well, a rider of one, the rider is normally a pair of hands, possessed by the horse, to collect the souls of the dying. But Drisana, his mare, spared him, when she chose a living rider, so he is still himself.
He wears a black cloak, it has magical properties to provide protection from all assaults to it's wearer. He has long sliver hair which he keeps in a ponytail, vivid green eyes, he has the scythe wick even not in use is a charm on a silver bracelet around his wrist. He has a small scar on his right check, earned when he was a mortal soldier, he also is normally a happy soul. When he chooses his face and hands appears as a skull and bones.
While serving as a rider he is immortal, if his physical form is destroyed, Drisana will revive him if she chooses him.
Drisana, a large black horse is his mount she is a very old powerful reaper spirit, she travels through the void to anyone and place to follow her orders, she can shapeshift and mentally communicate, normally only to her rider, for it is a disturbing experience to touch a mind so vast.
Moderate, but cleaver and sometimes witty.
He was chosen. He serves the mare, who serves powers mortals cannot understand. His memories are fuzzy, his mortal life was quite boring. He helps carry the souls of the dead to final judgement. But now the mare has other commands for him.