Sam and Lucifer, Dean and Michael. the Winchesters were meant to be the vessels, and this pic shows it such a beautiful way. thank god, Dean and Sammy are better and they did not kill each other but escaped the fate:P
"I try to be that good person you've always wanted, but I can't, I'm not. I've done, I do, bad things. I'm a bad person." He sighed and I shook my head. "You are not a bad person. You are a very good person.