The documentary HOLY HELL is now available for streaming through Netflix, Amazon Prime and iTunes. I finally watched it this weekend... it's a fairly good documentary. It does lack many insights but I think all the main points come through strongly one way or another. Creepy pathological narcissist. I think this film is worth watching.
In this particular case, the terms "mind control" and "brainwashing" are applicable. The cult leader used weekly hypnosis sessions to put his devotees into trance states, control his followers, seduce many of them, manipulate them, and so on.