As a side note, it would make an interesting story to follow to introduce Vonatar (obviously the game would have to be set a little closer to the Kai Masacre) and start him off as a sympathetic character, an idealistic young wizard, who is gradually corrupted. Maybe starting off providing some inconsequential information for a bit of money, and slowly compromising more and more until he finds himself a tool of evil.
I don't think I've ever thought of him as anything but plain evil. I think a story like this could have potential.