I believe him to be Jain Farstrider. Now while this might sound dumb consider a few facts. Farstrider is a hero of legend. The last place he went, from where he never came back, was the blight. Shadar Haran does not like it at shayol ghul and wants to leave. This implies that while he is respected by the dark one in some way he is not necessarily evil himself. The final fact is that RJ seems to really like odd twists and this could definately qualify as something weird and unexpected enough to allow in his novel.