Everything you touch burns. Evil writhes under your skin patiently waiting to strike; a snake in the garden of your own sanity. Bone, sinew and blood cannot sate your thirst for tranquility because you are no longer you, trapped in the vestige of a monster. A windup toy soldier that fell into the hands of the enemy, a child that grew dark living in the shadows of the ethereal plane. You slash, you mutilate, you murder. You have no choice because you are a slave now.
"I didn't mean to."
No soul resides in Dean Winchester, only the mark survived.