Disclaimer: I do not own Supernatural.

Title: The Choice
Summary: s11!AU. Dean says the unthinkable to the Devil in order to save Cas and spare Sam from his hold. Now it's up to what's left of Team Free Will to save Dean, if they can.
Genre: Angst/Romance
Rating: T - see warnings below
Pairing: Destiel
Spoilers: Minor season 11 spoilers. The finale does not happen. I repeat, the finale does not happen.

Note: So one night I saw a post on winjennster's tumblr about Lucifer!Dean. I couldn't resist writing this. And as a result of writing this, I have now become utter Lucifer!Dean trash. Hope y'all enjoy this!

Warning: will eventually contain discussion of depression and suicide. Please do not read if that bothers you.

Prologue:

"I'm running out of patience." Lucifer stared intently at Dean, who stared back at him angrily. "You can hate me all you want, but at the end of the day, the only way I'll leave is if you choose my next vessel. I can stay in Cas, or your brother becomes my bitch once again. The decision is yours."

"You can't do this. You need consent." Dean snarled.

"I don't have to give you the option, and quite honestly I'm throwing the rule book out the window. Angel consent's a formality – really was Dad's thing." Lucifer shrugged. "To be honest, if I wanted to, I could just take control of Sammy like that." he snapped his fingers and laughed. "…but seeing you take down Amara yourself was just…" Lucifer sighed, leering at him creepily. "Mesmerizing. So I'm being nice. I'm asking you to decide, Dean."

"No, you're kissing ass hoping we don't seal you in the cage." Dean retorted.

"And if you had a way to do that, we wouldn't be having this conversation." Lucifer scoffed. "So now it's down to the million dollar question: Am I staying put, do I use your brother, or am I just going to have to smite both of you where you stand?"

Dean glanced at Sam. His brother's face was white, his expression calm, but Dean knew Sam had to be terrified considering what he had been through, what his soul had suffered from the Cage. And Dean also had to consider Cas. No matter the fact that Cas had given his consent, no matter what Cas had believed in regards of Lucifer being able to win against Amara (which had proved unsuccessful of course), Dean had to bust him free.

There was no other option.

"How 'bout none of the above." he said finally, looking at Lucifer again. "'Cause there's another way we can do this."

Sam gaped at his brother. "Dean what the hell –?!"

"Shut up, Sammy," Dean snapped. "You want a body, you take mine. It's the other chosen vessel, a lot of other dicks would love to get their hands on it. Hell even Abaddon considered having me for a meat suit."

Lucifer's expression turned thoughtful. "Hmm…"

"Dean, don't do this." Sam protested. "We can figure out another way to beat him."

"If you figured something out I'm all ears, but this is it, Sammy. I won't watch him use you again, much less by force. And Cas needed freed ages ago, alright?" Dean exhaled. "This is how we do it. This'll buy time for you to figure out how to trap him again and send him back to that damn Cage, understand?!"

"Dean -"

"No buts, Sammy!"

"That's what he said," Lucifer quipped dryly, and both Winchesters returned their attention to him. "So what exactly is it you're saying, Dean-o?"

Dean's gaze was cold, unyielding as he stared back at the Devil.

"Yes."

The room flashed with a bright, blinding light, and then Dean knew nothing except darkness.

When the light faded and Sam lowered his arm that he had used to shield his eyes, he saw Dean and Cas on the ground. Cas was unconscious and Dean was groaning as though in pain.

"Dean?" he asked breathlessly.

His brother didn't answer him. Dean stood up, brushed off his jacket and turned to look at him, his face impassive.

"Not your brother anymore, Sammy." he said, and with a flick of his hand, Sam flew backward, crashing into the wall behind him where he stayed, pinned.

Dean grinned, but it wasn't Dean.

"You know, maybe I had your big bro pegged wrong from the get go," Lucifer said casually. "I mean, all the things he's accomplished. Woah." he looked down and nudged Cas with the toe of his boot. "He's alive. Brain's probably mush by now though."

"I'm gonna kill you," Sam ground out, straining against the power the Devil was using. "I swear. I will fucking end you!"

"Do that, and you kill Dean," Lucifer replied, smirking. "And you won't. Not even at the cost of the greater good. You forget, I know you too well, Sammy. Almost as well as Dean. Perk of being inside your head." He tapped the side of his head for emphasis, and then turned to leave. "Make sure you put Cas up in a good nuthouse, seeing as he's really not good for anything else now."

The power pinning Sam didn't let up until Lucifer had gone from the room, and once he was able to move, he moved quickly to Cas's side.

"Cas?" he said urgently, rolling the angel onto his back. "Cas, you gotta wake up, man. Give me a sign."

No response.

"Damn it, Cas." Sam shook him a little. "Don't do this man. I need your help. Dean said yes to Lucifer, and he's gone and – I'm spiralling man, I don't know what to do."

A few minutes passed and then Cas groaned, his eyes opening slowly, and Sam felt a rush of relief.

"Cas," he helped the other man sit up. "Take it easy, alright? You okay?"

Cas was quiet for a moment.

"You said Dean…he said yes to Lucifer."

Sam nodded. "He did."

Cas frowned. "Why?"

Sam shrugged. "To save us from being him." he ran a hand through his hair. "And now we gotta save him."

"How?" Cas asked.

Sam looked helplessly down at the floor.

"I don't know."

Hope y'all like this. Reviews are welcome!