Conscience
Dean's POV;
When I asked Benny to get Sammy out of Purgatory, I knew he never intended to come back out. But what was I supposed to do? Sam was down there with Bobby and there was no time to find someone else who knew how to get out Purgatory once they were in there other than Benny. I knew how much he hated being topside and I knew how much he hated himself. I knew because whenever I looked into his eyes it was like looking into a damn mirror. I told him that when he got back I'd fix it but what could I do? You couldn't fix someone that broken. I knew he wasn't going to come back through that portal with Sammy but I never let on. What would be the point? I doubt it would have changed his mind.
I think the night he fought with the other bloodsuckers who worked for his creator, he meant to die. It had to have been a suicide mission, or he was just crazy thinking he could have got through that unharmed. When he didn't die, he had to call me or some other guy would have found him and ended taking him to a hospital and then he'd be screwed.
Killing Benny is just another thing that will weigh on my conscience till the day I die. I wish there was one damn person that didn't get hurt because of me. The life of a hunter is lonely but when you do meet people it's always worse when you have to move on and leave them behind dead or alive. I wish I could see the light at the end of this goddamned tunnel.
I know this is really short, oops, sorry but I hoped you enjoyed it anyway