if soulblighter ripped off his own face for the dark gods or something, then thats all well and good but, it doesn't seem terribly origional, even in the game it mentions it being a dark ritual, so it has obviously been practiced before.
that brings me to the point made many times before about the fallen lord called the faceless man, this could be the name for soulblighter, or it could be the name for another fallen lord who performed the same ritual.
also, this ritual could be something not dedicated to the dark gods, but dedicated to the leveller spirit, essentially giving the person an abridged version of the leveller power, this could be how moagim became the leveller twice(notice he was called the faceless terror), and would have given soulblighter to overcome the entire province in one year, because levellers are not supposed to come in that close succession.
Gothmog