The search for Treachery's End.

[William Wallace]

My guildmaster has that weapon. He got it from Tormenta, so maybe try there. In the end though, it's all luck, luck that I don't seem to have since I haven't found any famed/legendary cursed blades (other than the one you get from the quest).

The best thing to do(In my opinion) is to just loot in a spot for a few hours, like in the treasure room on Tormenta. Using steel shot + blunderbuss can usually take care of 2-3 of the tormenta guys in 1 shot, because of their close proximity to each other. Just have to get lucky.