I think it would be fair to be able to get 35% of what you would normally get for a mastered weapon. For example, if you use voodoo, and get 100 rep, 70 of that rep would be taken away. Kinda like texes, lol... although I wouldn't know
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Shhlatkinz 
The Guardians
(remake of The Brotherhood)
Notoriety 40
Pirate Master
Toontown
Cool Corny Electrofoot, Nacho Average Pig, Cool Corny Electrofoot Blak