It's impossible for me to turn down loot increases so Malefactor is the easy pick for best, and not being mauled by wolves from farther than I can see is a nice bonus. By that logic Blackguard should be my least favorite, but I feel like Clockmaker is the worst. While it shares the same penalties as Malefactor, the benefits mostly go towards a specific part of endgame. I find that the start is the hard part and the endgame can be handled with appropriate preparation, so I don't see much point in Clockmaker. It just feels like making yourself weaker for nothing.
