My Kingdom Come
Ever since Dean turned into a Knight of Hell, he wanted to be King. After Sam died in the process of trying to save him or cure him or whatever, Dean went right down to Hell to see the state of things. When he got there, he fully understood what Abaddon was talking about. Having Crowley, the glorified salesman, as the King was a joke. Dean quickly over threw him. His goal was to rebuild the Knights, but not a single soul he had come across was vibrant enough.
Dean now spent his days torturing the souls of the damned, which he had to say was pretty freaking fun. He always kept his eyes black to scare the shit out of people. It was kinda his image. Day in and day out, he would torture the idiotic souls that sold their souls. Like one sold his soul for the greenest grass in the county. Another sold her soul to be a virgin again. Dean could understand that one.
One day, Dean was strolling into the Big Room, the place where the new idiots were broken in.
He brought out his cart of devices. "So what're you in for? Bigger package, more money, love, I've heard them all."
A raggedy voice comes from the hooks and chains, "Hello, Dean."
Dean's black eyes widen. He whips around to see him. Castiel is the person he would be torturing. His soul the brightest he had ever seen, almost completely blinding.
"Cas? You are the last person I thought I'd see here."
Cas winced as the hooks dug deeper into his skin.
"I had no other choice."
Dean chuckles sadistically.
"Well why'd you sell it?"
Dean slices a line down the middle of Cas's chest, making Cas shout out a bit.
"Why? To be with you, Dean."
Dean stops. "What?"
"There was no cure for the Mark. I couldn't save you. I'm sorry, Dean."
Dean backs away a bit.
Cas groans as the hooks stretch under his skin. "I'd rather have you cursed or not, remember?"
Dean grimaces to conceal the wobble of his chin.
"You know demons don't have feelings right?" He rubs salt into Cas's wounds, making him cry out.
"Neither do angels. But fell for you."
Dean's eyes get wider, and then he snarls.
"No you didn't, don't lie to me, Castiel. Even Sammy stopped loving me. That's why he started with the drinking that led to his death."
"Dean, I'm telling you the truth! I would rather go to hell, than go to heaven, because what kind of heaven didn't have you?"
Dean clutches the knife tighter.
"I love you, Dean."
A tear runs down Dean's cheek, and then he starts to tremble.
"SHUT UP," He shouts, and plunges the knife into Cas's heart, watching the light drain from his blue eyes, tears streaming down Dean's face.
Every day, the only thing Cas would say before Dean killed him was, "It's okay, Dean."
Every day, Cas would tell Dean about what he meant to him.
Every day he told Dean that he loved him.
Every day Cas told the story of how he fell in love with him when he was reconstructed Dean's soul.
And every day, Dean would kill him without a second thought. He was merciless.
Until one day, he wasn't.
It had been 150 years since Cas first entered hell. Cas was at the very brink of turning into a Knight, just one kill away.
"Dean?"
"What."
"I… I'm scared."
That was it for Dean. His eyes slowly receded to their candy-apple green. He put the knife down, and walked over slowly to Cas.
"I'm sorry, Cas. I have to."
"Why? Why do you have to?"
Dean's now green eyes welled up.
"Because I don't want to live without you anymore. Every day you said, 'It's okay, Dean' and 'I love you, Dean.' And you would tell me about how you fell in love. And it worked, okay? It worked, God damn it. I love you okay? I love you too, Castiel, Former Angel of the Lord, and my best friend. I love you."
The tears were streaming down his face now.
Cas's lip trembled. "Dean."
Dean walks close with the knife, murmuring to Cas comfortingly. "Cas, just one more time. One more time, and all the pain and suffering is over. You can stand by my side and rule Hell with me. I would be the happiest black-eyed bastard alive if you let me. I know it's scary, Cas, but I promise you. I'll love you for the rest of my life."
Cas was sobbing now, nodding vigorously.
"Okay. I love you, Dean. Please just… Do it fast, okay?"
Dean nods. "I will. I promise. Just…Please don't watch. "
He kisses Cas's forehead, and Cas closes his eyes.
Then, Dean plunges the knife into Cas's heart, sobbing all the while, and mumbling "I'm sorry," over and over.
He steps back, sets the knife down, then takes off the chains and hooks, watching Cas's body heal itself of all the wounds he had inflicted.
Hours passed and Dean began to worry. Maybe he wasn't as strong as Dean thought.
Days passed, and Dean was spiraling out of control, being more ruthless than ever.
Weeks passed, and Dean knew he failed. He walked over to Cas's body and hugged him, rocking back and forth, sobbing.
"I'm so sorry, Cas. I thought you were strong enough. But apparently not, and now I've gotten you killed, just like every God-forsaken thing I care about. I guess this is—"
Dean chokes back a sob.
"I guess this is goodbye."
He kisses Cas gingerly on the forehead.
"I love you, Cas. I'm so so sorry," he whispers. He stands up and walks out, closing the door behind him. He puts his head against the cool metal and sobs... Then he screams. A scream so deafening, so broken, and so heart-shattering that every demon, in hell or otherwise, has no choice to stop, listen, and cringe.
Dean turns to leave but runs into someone.
His eyes turn black in anger, his fists clenched at his sides.
"You son of a b—"
"Hello, Dean," says a familiar voice.
Dean's angry black eyes recede back to green and he looks up into sapphire blue eyes, which quickly turn black. Standing there is Cas, and God he had never looked so beautiful. His dress shirt and tie are now black, his trench coat is of the same dark hue, and his hair is so perfectly ruffled. His black eyes flicker blue for an instant under Dean's loving gaze.
Dean laughs through his tears, kisses Cas roughly, then just keep their foreheads pressed together.
Dean smiles, and looks into Cas's beautiful black eyes.
"Hello, Castiel."