The serial killer in Relentless (1989) was able to grapple and control his victims enough to make them hold the murder weapon(s) and force them to finish themselves off.
I am unaware of grapple rules that allow such a thing. Is there a way I can build a character who can do this?
Any level, any class, and any book is allowed. I would rather rely less on magic if possible. I will customize the campaign around him.