Ok, I've had a good think about it - and this is what I'm going to base my decision around.
It's gotta be Nurgle71. Based on the following:
Its not really important now but I do have the power:
1x Shot: Watcher. I went to see if there is any action around Mal but got No Result. Didn't think it was worth mentioning. (probably wasted it too, should have got someone else.)
Why on earth would there be a 1 shot watcher mason in the game? That is just such a bizzare power combination that it makes no sense. All it does is allow Nurgle to explain away the reason why he showed up on DJcodex's observations, and prevents him from being called to make another use of his ability to prove that he has it. Not to mention that we appear to already have another Watcher in the form of DJcodex. I don't buy it at all.
Any chance he has a power that shows up innocent ? I'm suspicious of Vesh because of his interest in getting the Masons (us!) lynched. Next thing, boom! A mason is dead. Just a little bit iffy...
One of the 3 masons gets killed and Nurgle is the first to point it out. This smells like him trying to create a diversion by killing one himself, not to mention that he would know Rocdocta would flip town, which furthers his cause.
Sorry mate but Greenfuji just confirmed with me via Pm that the message I received from Nurgle was indeed a legit message as part of our Mason power role.
To clarify, I confirmed with Bloodlust that I received his PM and that he is communicating correctly by including all his mason's and myself in the PM.
FINAL NOTE: After both Bloodlust AND Nurgle71 claimed to have used their mason powers to communicate with each other - Greenfuji made a careful point of saying that he had communicated with BLOODLUST (not Nurgle) and confirmed that he was communicating correctly as a mason.
I'm putting it on the line. This is the endgame.
Lynch vote: NURGLE71