"How about Jephthah?"
Edit > Find > Jephthah
http://glenster1.webs.com/basicspage2.htm
"Who in his right mind would design content that asks kids to kill someone?"
Slender Man is a horror figure depicted in various works of fiction including
games. The point is to avoid him--not kill children. Imagine being 12 and giving
something like that, or out of a Hitchcock movie, as an excuse for attempted
murder. Unsurprisingly: "The attackers were charged as adults and are each facing
up to 65 years in prison."
https://www.youtube.com/watch?v=04FL6MoMU7U
https://en.wikipedia.org/wiki/Slender:_The_Eight_Pages
https://en.wikipedia.org/wiki/Slender_Man
The closest to the excuse of the girls I could find is in the background of an
antagonist of the 2nd game of the series, not something given as something the
protaganist can do to become an assistant of the Slender Man:
"Kate - friend of Lauren, she becomes the secondary antagonist for most of the
game, but is also playable in "Chapter 4". Her mother has recently died and she
has decided to sell the house, prompting Lauren's visit, but disappears. Prior to
the events of the game, she had visions of the 'Slender Man' who she shared with
her friend CR. The night before the events of the game, she was attacked in her
home but managed to escape, as revealed in "Chapter 4". She was subsequently
turned to serve as his "proxy", or an assistant of sorts."
"The Slender Man - the main and faceless antagonist of the game. Facing him
causes the camera to glitch and distort, intensifying as the player gets closer.
In the game, it is also shown that he can turn his victims into "proxies", or
assistants of sorts."
https://www.youtube.com/watch?v=XTnRcgtP1xc
https://en.wikipedia.org/wiki/Slender:_The_Arrival
I don't think you can play as an assistant, though. This YouTube video shows
someone goofing around with a proxie:
https://www.youtube.com/watch?v=ha4zi3SqV1w