Instructor of Dark Magic?

I am looking for an instructor in Dark Magic, specifically someone who has had thorough training in Coercion or Persuasion. I have practiced on my own for a few years now and am in need of someone who has experience in these areas. This is a serious question, so please keep responses serious. I understand that magick is not "black" and "white", rather it is shaped by the user and deemed "good" or "bad" accordingly. I am very interested in any aspect of the darker side of magick and would like to find a teacher or instructor who would share their knowledge and experience with me.