A/N: Hey this is just a little short one-shotish story of demon Dean. Seasons 1-9 spoilers.
"You're gonna die! And this, this is what you're gonna become!"
If I would have known seven years ago just how right my subconscious was, I might have changed my ways a little. I might have let Sammy die earlier this year. I might have been a better person. But I didn't. I went to Hell, and came back! I figured that I was done. I had survived to live my life. I stopped the apocalypse. Even after my baby brother fell into Hell, I was happy. I had been able to have a family, a life away from hunting. But even so, Sam had escaped the pit, only to have realized that his soul had been forgotten. But once again, everything was put back into place. I never thought I would become a monster, never had the time. I even went to Purgatory, came back, and still was not a demon.
Who would have guessed that a little tattoo on my arm could make such a drastic change? I had bounced back from so many situations with my humanity still intact. Why should this be any different? I had failed to protect Sammy from having to complete the trials, but I could not fail him this time. Taking on the Mark of Cain was my responsibility. I had to do this. The beginning of the year had started with nothing but bad decisions. I almost got Sam killed. If only I had been thinking straight, I might have let him close the gates of Hell forever. But then I wouldn't have gotten to try out this new life. I wouldn't have gotten to howl at the moon for once in my life, with no care in the world.
Now I am finally free. Free to let my little brother finally have a life where I don't try to bring him back. He can finally leave me, like I always feared he would, because everyone did. Mom left me. Dad left me. The love of my life left me. Her mother left me. Lisa left me. Bobby left me. All my friends left me. Sam was just the one person I kept dragging back, the one person that, no matter how much he struggled against me, no matter how much he fought me, I forced to be my prisoner in this world so that I wouldn't be alone. I just couldn't be alone. All my life, I knew that once I was alone, I was done. I couldn't be alone. I would turn into a monster if I let myself become lonely.
Maybe that's why, all through my life, I had seen a different girl every night. I acted so alive and overconfident so that no one would see how broken I was. I would let no one see that my dad and brother fought every night, that they tore me apart, that they didn't even notice how much their fighting killed me. Maybe that's why I was so screwed up; the weight of the world was on my shoulders. I blamed myself for other's problems. I thought that I had somehow caused their pain. Looking back, I now know that I was right. For a while I had tried to find rational reasons for why everyone in my life left me. But in the end, I knew it was me. I was unlovable. But that doesn't matter anymore.
I have a new life, a new opportunity. I don't have to worry about anything anymore. I can have as much fun as I want, whenever I want. You can let me go now, Sammy.