Impossible love ?

Dean Winchester, every Hunter knows him and all supernatural beings fear him.

Alone with his Brother he hunts any monster in the world, but he meets abel's brother Cain and gets the Mark of Cain. along with the first blade, it slowly makes him crazy. Does he have the power to repress this or will the story be repeated of the big and protective brother who kills his own brother?

and what if a girl comes into this mess?

Madison Wilson. After her parents were killed by a monster in front of her eyes, she starts hunting.
After a while, her uncle contacted her, Madison is on the way to her uncle, who's also a great hunter..
there she meets the Winchester brothers..

She never let any Guy near her and her heart.. will dean change that? will she change his trust issues?

And the most important question: Do Sam finds a way to heal Dean from becoming a Demon?