After Vasher was being tortured by Denth, he realizes that Denth isn't happy about it. That some good still exists in him, but badly beaten down and even more tortured than Vasher is right now.
Denth: You think I should just go back to the way I was before? The happy, friendly man everyone loved?
Vasher: You were a good person
Denth: That man saw and did terrible things. I've tried, Vasher. I've tried going back. But the darkness...it's inside. I can't escape it. My laughter has an edge to it. I can't forget.
Vasher: I can make you. I know the Commands (Denth pauses, shocked) I promise, I will take it all from you, if you wish.
Denth: (stands with his sword lowered, thinking for a long while but then shook his head) No. I don't deserve that. Neither of us do.
- Also, the bit leading up to the torture.
Vasher [quietly]: Torturing me won't bring her back.
[turning, blade catching the moonlight]: No.
- Becomes potent Fridge Horror when you remember that Denth is torturing his brother-in-law, and the only family he has left.