SO: Disclaimer: I do not own Supernatural (unfortunately)
Also, this is my first story, so please be gentle :)
Oh, hey look, it's not even that bad... It's not even that bad, alright? Sammy, Sam! Hey, listen to me, we are going to patch you up okay... You'll be as good as new. Huh? I'm going to take care of you, I'm going to take care of you! I gotcha. It's my job, right, watch after my pain-in-the-ass little brother... Sam... Sam... Sam! Sammy!
"You know Sam, this could all be over right now, all I want is an apology," the fallen angel whispered softly, his eyes filled with compassion.
Compassion Sam knew was false.
Sam spat a glob of blood at Lucifer, "Never!"
Lucifer frowned and slowly, delicately, wiped the bloody spittle off his cheek, staring at his fingers for a moment. And then, turned his slightly crazed eyes back on Sam and mercilessly twisted the knife in the vessel's gut, reveling in the shriek it brought forth.
"Delicious. You know, Sam, if you had just been a good vessel we could have been friends. After I had cleared the world of the flawed humans and the filthy demons we could have made a utopia."
Sam laughed. "You forget, I'm one of those flawed humans you hate so much."
Lucifer smiled kindly at Sam like he was a small child who needed to have even the smallest of things explained to him carefully. "Yes, it's true Sam, you are human, but don't you see? We are two of a kind, wanting the same thing in life: acceptance from an uncaring father, respect from our brothers, the chance to make our own decisions."
Sam let out a small groan when Lucifer put pressure on the knife, swallowing back the blood that burbling up his throat.
"You might be right about something, I did want Dad to accept me for who I was, and I wanted to make my own choices, but you know what? Even if I don't have respect from my brother, I know he's always going to be there for me, 'cause that's his job."
Lucifer's gentle expression melted into pure rage and he viciously bore down on the knife, slicing cruelly through the flesh. "There is no one here to help you, Sam. Dean is not going to come for you, you will never escape and I am going to keep pushing you until you break. Until you forget the very existence of that pathetic waste of space!"
With a roar, he ripped the knife up, shredding through viscera up to the lungs, watching with satisfaction as the soul beneath him twisted and writhed and gasped for air only to choke on his own blood.
Lucifer would not have been grinning quite as widely, been quite as smug if he had known what was going through the struggling soul, as already the wounds healed, readying for another round of torture: "Bitch""Jerk."