Manipulative Mentor

The Manipulative Mentor is a manipulative, controlling mentor that exploits the student for his own gain. While emphatically not a good mentor, a Manipulative Mentor is usually not so much trying to pass on his legacy of evil (unlike the Evil Mentor) as control (and exploit) the disciple by any means possible, from just plain being a Manipulative Bastard through overt Mind Control to More Than Mind Control, often with a side of Stockholm Syndrome and Mind Game Ship. This often also involves being The Chessmaster, or at least The Strategist, in terms of PR campaigning.

This may cut both ways, though, since the follower sometimes also serves as The Muse to Manipulative Mentor, who may be Hoist by His Own Petard as a result, unable to repeat his success without the student. A Manipulative Mentor is liable to end up more dependent on the disciple than vice versa. (Lima Syndrome is an occupational hazard, often along with some form of Muse Abuse, though a Manipulative Mentor may not himself be an artist of any kind.) Expect additional layers of dysfunction if a Manipulative Mentor is also a Stage Mom (or Dad, since a Manipulative Mentor is nearly Always Male), in which case shades of Knight Templar Parent are also likely. A Manipulative Mentor also tends to pursue success so ruthlessly that bystanders are maimed. A Manipulative Mentor may also be The Man Behind the Man.

A Manipulative Mentor is more likely than the Evil Mentor to be Obliviously Evil. Watch out for appearances of "But I did it all for you!" and, conversely "I made you!" (for extra points, add "and I could break you just as easily").

On the other hand, a Manipulative Mentor is relatively unlikely to suffer from Mentor Occupational Hazard, unless it's Death by Irony, and may be a Karma Houdini. Occasionally they will have a What Have I Done moment, and may be Driven to Suicide by the follower's abandonment, but such crises are almost equally likely to turn into an Ignored Epiphany.

A Manipulative Mentor is a frequent, even near-inevitable, cause of Rage Against the Mentor. Since a Manipulative Mentor job is usually to provide their ward with worldly success, and Ambition Is Evil, What Have I Become? moments (where applicable) tend to turn into What Have You Made Me moments, kind of like I Hate You, Vampire Dad but with less fangs.

Often claimed about Real Life managers of actors and singers/bands, sometimes by the manager, presumably due to Evil Is Cool.

Examples of Manipulative Mentor include:

Film

Peter O'Toole played a (relatively) benign version of this to Jodie Foster in Svengali, a movie inspired by but not based on Du Maurier's novel.
Josef von Sternberg is often claimed to have been this to Marlene Dietrich.
In the 1950 movie All About Eve, the character Bill Simpson (played by Gary Merrill) says to Eve Harrington (played by Anne Baxter), after she tries to seduce him, "Names, I've been called — but never Svengali."
In a Three Stooges short film "Hokus Pokus" (and Flagpole Jitters), Moe (Moses Horwitz, AKA Moe Howard) introduces actor Jimmy Lloyd, who was portraying a magician, as, "Svengarlic: He'll take your breath away!"
Arguably Dr. Frank-N-Furter to his harem.
- He delivers the line above to Rocky:
  - "I made you, and I can BREAK you just as easily!"
    - Arguably an inversion; the Svengali tends to Man Behind the Man while Franknfurter tends to collect groupies to support his divahood. This line was delivered to a sideshow who was stealing the spotlight.
In the 1946 film Deception, composer Alexander Hollenius (Claude Rains) is the musical mentor of Christine Radcliffe (Bette Davis). He is none too pleased when Christine suddenly decides to marry a cellist (Paul Henreid), and he invokes their mentor relationship when begging her to return to him. When that doesn't work, he puts the couple through a series of vicious mind games.
Arguably, Grizelda in The Court Jester. There's certainly hypnotism involved.
- Tails of lizards, ears of swine, chicken gizzards soaked in brine, On your feet, be not afraid; you're the greatest with the blade! *SNAP*

Literature

The Trope Namer, from Du Maurier's Trilby. (Sidenote: Readers seeking it out should be ready for Values Dissonance, given that Svengali's Jewishness is played out in a pretty similar way to that of Fagin in Oliver Twist.)
Fagin may count as this to his boys in Oliver Twist.
Erik, the eponymous Phantom from The Phantom of the Opera is this to Christine. Since he actually is a good music teacher he may also qualify as a Broken Pedestal. Due to the similarity of the stories some regard the Phantom as being Svengali with the Serial Numbers Filed Off.
In-universe, the supernatural law enforcement rumor mill in the Anita Blake novel Skin Trade has Edward as this to Anita. Or at least that's one of the rumors. "I heard he was more like your Svengali," is the response of one Las Vegas cop to Anita referring to Edward first as her partner and then as her "rabbi" (mentor, one assumes).

Live Action TV

In an episode of the sitcom Seinfeld, entitled "The Wallet", Elaine refers to her psychotherapist boyfriend as a "Svengali" because he wields a powerful mental influence over her. She mispronounces the word as 'svenjolly', causing Jerry and George to mock her.
The Master in Doctor Who has svengali traits, being a master of hypnosis. Someone asks the Third Doctor if the Master is "a bit of a Svengali" and the Doctor replies "more of a Rasputin".
In the season 1 pilot of the Moonlight TV series, entitled "No Such Thing as Vampires", Beth interviews a suspect who refers to another character as a "Svengali" who brainwashed students, using literary references to vampires, sex and dark desires and seduced them into his cult.
In the NCIS season 3 episode "Silver War", Special Agent Leroy Jethro Gibbs consoles Mossad officer Ziva David about her half-brother Ari Haswari, whom she had killed, by describing him as a Svengali.
In Season 9, episode 6 of Law and Order Special Victims Unit, the captain refers to a perpetrator as a "Svengali".
Rare female example: Frasier's evil agent, Beebee.
In Name Only (Entry Pimp) example: Svengoolie took his name in part from Svengali.
Randall Fuller, the self-help guru with a generous helping of More Than Mind Control in the Law and Order: Criminal Intent episode "Con-Text."

Music

Malcolm McLaren cast himself as this to the Sex Pistols, and later to Bow Wow Wow.
Robbie Williams claims Nigel Martin-Smith as this to Take That the band.
And "The Colonel" Tom Parker to Elvis Presley.
And Kim Fowley to The Runaways. Heavily lampshaded in the recent film, where Fowley also claims I Meant to Do That in response to their Rage Against the Mentor dumping of him.
The Human League's "Don't You Want Me" is a dialogue between a Svengali and his increasingly-rebellious mentee.
Considering he was manager of one of the biggest rock acts of all time, Brian Epstein, manager of The Beatles, was by all accounts a subversion of this trope, being a rather mild, unassuming fellow genuinely devoted to 'his boys'. While he personally would never have dreamt of exploiting them, it has been noted that his lack of business acumen did see them come much worse off from many business transactions (particularly concerning the rights to their music) where a more savvy manager along the lines of this trope might have been able to get them better deals.
Eugene Landy to Brian Wilson.
Herbie Herbert to Journey. Dear god, the man claims all the credit for founding Journey, to the point where he was playing group members off each other in a continual power struggle to keep his "creative" vision. Interview here.

Video Games

Kriea from Knights of the Old Republic II to the main character. Fridge Horror sets in once you've replayed the game and seen just how much of the relationship between these two characters falls under More Than Mind Control. Depending on the theories you subscribe too, it may have been done all for revenge or for the greater good, but only two things are really certain: firstly, that they seem to actually care for each other in a twisted fashion, and secondly, it worked.
Master Li in Jade Empire, so very much.

Western Animation

In the Season 2 episode of The Venture Bros. titled "Guess Who's Coming to State Dinner?", Col. Bud Manstrong angrily calls Brock Samson "Svengali" when the colonel finds his mother passed out in Samson's lap.

Real Life

Charles Manson, who roped at least two-dozen young people into his murderous "family."
Charles Sobrahj, a celebrity confidence man and serial killer who used methods similar to Manson's to prey on Western tourists throughout South and Southeast Asia in the 1970s.