Hiyay, so this is my first fan fiction ever so pleas be kind.
Some spoilers through season 8. Basically inspired by a scene from "heartless" and deans comment about literal hearts being ripped from chest as the only kind
That interested him and I thought that's how dark he can be.
Anyway, no ownership of supernatural or characters, just having fun.
"You left me in purgatory Sam; you were off living some"Leave it to Beaver" life while I was stuck where horror movies go to die. Didn't any of that feel wrong?"
Giving an exasperated sigh Sam turned to his brother, "Of course it felt wrong, our whole lives have felt wrong…but she didn't."
Dean turned from his brother but Sam could not let thing go unsaid again.
"Dean I get why your pissed, but I know that if I had made my way into purgatory you would have flipped out on me then too." Taking a deep breath he continued "I know it's no excuse but Dean, The last time I lost…The last time you were gone, I would have done anything to get you back; I would have traded my own soul. Dean you taught me better than that…and I still almost destroyed the world."
Then meeting Dean's gaze, "if I haven't learned those lessons by now, then I've failed at being your brother. I couldn't save our friends, and I couldn't save you…So I saved a dog, and lived a life that you…you really deserve; because if anyone deserves a good life it's you Dean."
Dean focused on the space beside Sam's head, like he was a million miles away. "Sammy I wish I could be that guy you're talking about. You don't know how much I wish…but there is too much blood on my hands. You went to hell and found penance, but Sam I went to hell and discovered my true nature. No, don't try to deny it…it's true. There is something so dark in me that dad should have given you the warning, so now all I can do to counteract this darkness is to hunt these monsters down."
"And save people, right?" Sam asked
Dean's eyes locked with Sam's, there normal green taking on a strange darkness, not unlike the beast they hunt, dean replied "Yeah… of course Sam, of course it's about saving people."
And something about those words, so detached, caused a shiver down Sam's spine.