Dean ripped out the first blade from Abaddon's skull and held it up to night sky in victory, letting the moonlight shine on the blade as the blood trickled down his arm.
"Put it down!"
Sam was running towards Dean as fast as he could, filled with fear. He could already see the insanity and rage building up in Dean's eyes.
"You did what you had to do. Now stop! Drop the blade!"
Dean slowly lowered the blade, but he couldn't let go. The power that ran through his veins when he held the blade was just too precious for him to lose. Then, he heard some small whispers in his head.
"Kill him."
Dean looked around to see who had said that, but only Sam was there. It kept on repeating, with a soft and gentle tone.
"Kill him now. You have to. You must."
Sam yelled at Dean to get him to listen, but there was no use. The voices in his head became louder. He fell onto his knees, covering his ears, while still gripping tightly onto the blade. He could hear shrieks and screams for one simple command.
"Kill Sam."
Dean looked at the blood-stained blade. He knew the voices wouldn't stop until he did as it said, but he just couldn't do it. He couldn't kill his own brother. Still, the voices were too much for him to bear. Dean knew there was only one way this would end without killing Sam, and he had to do it.
"Dean, what are you doing…?" Asked Sam, terror filling his heart.
"I'm so sorry. The voices just won't stop."
He held the blade with both his hands and slowly lifted it above his head.
"I guess this is goodbye Sam."
With one quick swing, he swiftly thrust the blade into his chest, and fell straight onto the ground.
"Dean! No, no, no. This can't be happening."
Sam ran straight to Dean, and cradled his body in his arms.
"Dean. Dean! Say something! Say anything!"
Dean coughed up some blood, and gave no answer. The blade fell from his fingers onto the ground, and he stared back at Sam with lifeless eyes. Tears were streaming down Sam's face, filled with pain, anguish, and most of all, regret. All the things he never said. All the things he never did. All of those memories swirled around inside his head as he watched his brother die in front of him.
"No. You can't die. Not now. Not here. Please Dean. Please… Don't leave me alone."