Dar

Dar is one of Crowley's trusted demon girl

History
A captured Dar is strung up on tree and taunting taunting Sam Winchester about the acts he has committed. Sam threatens to torture Dar some more with a knife, unless she gives him information on the whereabouts of Crowley. In an act of defiance Dar tells Sam, "eat me" after which Sam stabs her in the gut and twists the knife, demanding to know where Crowley and Dean are. When Dar say she doesn't know, Sam slices her neck and collects the blood in a plastic cup, and demands she make a call to Crowley, as she begs Sam to stop he becomes more agitated and demands to know where his brother is.

Her fate after the torture is unknown, but presumably she killed after it.

Weaknesses

 *  Devil's Trap - She bounded effectively by a pair of handcuffs branded by devil trap and binding link.
 *  Iron Knife - Although not killed her, she badly wounded by it.