The mafia will not be revealed by the duel mechanism, and there's a reason why. Remember the whole background. There's former Gods and Demons, as well as humans working for Angra Mainyu. Now, the duel mechanism will give an indication of strength of role- and if a player is killed in the duel, that may indicate an, shall we say, abnormal role, as most, including mafia, will attempt to show restraint to avoid a larger spotlight on them. There will be some, but not a lot, of info given away based on how they fight. I felt this would accomplish a couple things:

1) Give a bit more significance to the role of Director. Bearing in mind that I plan on doing the writeups(though I'll take a few hints if the players desire), so that bit of the director's job is moot. Further, this way, the director will have a much more direct influence on the game. Of course, as I figure it, any director who consistently chooses the player the town found least suspicious is one not long for the world. The one override mechanism I have against the director's power is that if he is in the top two in voting at the end of any day phase, he will be stripped of power, and forced into a duel to the death against his peer in "suspicion garnering". Regardless of who wins, the town will then elect a new director.

2) Be a way for both the town and mafia forces to gather a bit of information. Not much a lot, but enough for people to get a feeling of "oh, this guy is probably a power role". There's one more bit of info it would help some people with, but I shan't reveal, as its secret.