User blog comment:FTWinchester/Season 9 concepts/@comment-86.132.20.55-20140115183552/@comment-86.132.20.55-20140121234834

Got an idea based on the fact an episode is called Thinman.

Ok it would include the Slenderman but not in the way mentioned above. It would involve cursed objects. Ok the brothers are investigating a town where there have been murders during an urban legened festival. Its a tricky case because all the people running around as monsters make its hard to tell if the killer is a creature or a random nutter. They are eventually attacked by a creature resembling the Slenderman that only escape by chance. It has sharp claws and can teleport and can heal. They find the creature has been created by someone wearing a cursed mask for the play.