She didn't die immediately.
The brothers thought she did, and they left, her body collapsed on the convent floor.
She wasn't quite sure how long it took to die, or if it was just the rush of adrenaline extending several seconds into an eternity.
It felt like an eternity.
It had worked, and that was the important thing, she tried to convince herself. She had tricked Sam and Dean, freed Lucifer, and started the Apocalypse. More than any other demon could dream of accomplishing in their lifetime.
It was a victory, and she managed to roll that hollow word off her tongue.
Victory, she whispered, to no one and nothing.
A word so sweet, so full of hope, yet so hollow and small.
She breifly wondered if the Victory was worth the sacrifices.
Lying to demons. Definitely. No demon deserved anything from her, even something as simple as the truth.
Facades and tricks all the time. She had always wanted to be an actress. She would have smiled at her lame joke, but she couldn't move.
Hurting her precious Sam. She faltered.
There wasn't supposed to be an attachment, there wasn't supposed to be emotions. She was supposed to meet him, lie to him, feed him her blood and prepare him to start the end of the world.
And yet, a simple mission and a few simple lies turned into so much more.
She's not sure what prompted the long dead, sweet feelings to rise up in her. She wasn't sure why she liked him. She wasn't sure why he interested her so.
She wasn't sure why she fell in love with him.
She wasn't supposed to.
"Why not, because it's bad, and it's wrong, and we shouldn't?"
But she did. She had no idea if he loved her, but for her last, dying moments, she decided to pretend he did.
Laying immobile on a convent floor, she denied the truth. Those weren't Sam's familiar hands holding her in place when Dean plunged a knife into her, just a few moments ago. He didn't loathe her for using him. She never had used him in the first place. It didn't happen. None of it happened.
She shut her eyes, and thought on one of her favorite memories, attempting to convince her dying mind it was happening over again. She was lying in a bed, she didn't need sleep but it felt so beautiful, wrapped up in a thick plush blanket, Sam lying beside her, his strong arms wrapped tight around her, placing a soft kiss to the back of her neck as she drifted off.
And then merciful blackness filled her vision, the throbbing pain from her wound stopped, and Ruby was slipped away into death's embrace.