The Anti-Body

The Anti-Body is an Anti-Villain turned Anti-Hero in the OneHundredYardStare Slender/ARG series.

Story
While originally stalking the protagonists and attempting to kill them to stop the Slender Man's infection, he decides not to, and allies himself with them. He then serves as a protagonists, by helping the girls and even letting Ellie defend herself while she's out in the woods.

Unfortunately, Ellie goes insane and murders the Anti-Body.