Ruby
Why do you think I'm doing this for you? I understand. I'm not without emotion either. I feel, just as you do, and I understand your pain. That's why I let you see him.
It's also why I let him see you. He'll stay quiet for me. It's easier to focus when he isn't squirming around.
I know how to fix it. It won't be pretty, but I think there's only but so much left of Dean Winchester. There's only one way to end his pain.