Dean walks gracefully across the green fields.
The wound on his stomach continues to bleed but Dean has long forgotten about it. The final battle had taken everything from him.
Sammy, Cas, Chuck, Kevin even the Impala was destroyed. His breath begins to quicken. Dean falls to to ground and lies against a nearby tree , the grass is soft and gentle on his skin. All Dean can think is that it's finally over, he's done what he was destined to, stop the Apocalypse. But at what cost he thinks. The image of Sammy on the ground flashes through Deans mind. There was so much blood, Cas was already gone at that point, his wings imprinted on the ground where he laid. Dean erases the image from his mind and takes his final breaths. His eyes shut. He awakens to a hand on his arm "Let's go" Sam says with a sympathetic smile. Sam stands there uninjured and glowing. Dean stands and looks back to see his body lying on the ground, still and pale. One look back at Sam and he realizes, It's over he's gone. Dean and Sam begin to walk away, Dean see's Cas in the distance, he's stands there with a smile on his face. He looks as he did the first day him and dean met, powerful and healthy. As Dean gets closer he see's other figures in the distance.
Mary, John, Jo, Ellen. Everyone, everyone who Dean had ever held close. Mary embraces him. "It's over Dean, You can rest now."
she whispers. Dean sighs in relief and laughs, He's free, his work is done. Dean parts from the hug and smiles. He and the rest of his friends and family walk into the distance. Although nobody would truly know what they had all done for the good of the people on earth, the sacrifices they made, they pain they had endured. They themselves would know, and that's all that really matters in the end.