Devil on Your Shoulder
From NsdWiki
Expoint Bonus: 2
You are more aware of your darker impulses than most. It's not that you can't be good – you know all about good and evil – but your evil side is WAY cooler. You take a -4 penalty to Self-Control checks, and the GM should tempt you frequently.
Devil On Your Shoulder works especially well with Avaricious and Sadist