All commentary below by Dustin Acton (2006).
Witch powers: can drive men crazy, can control alternate self, ages slowly.
This movie is a very poor adaptation of the famous Carlos Fuentes short story, "The Aura." An out-of-work Sergio believes that a strange old woman is following him. He then discovers a classified ad that describes him and the work he is looking to do (manuscripts to be put in order) almost exactly. Responding to the ad he finds the very lady he believes has been following him. Unlike the short story, this aspect of the plot is handled very heavy handedly, with Sergio immediately assuming that Consuela wishes to hire him as a gigolo. At the house the old lady, Consuela, tells Sergio that she wishes to hire him to put together her late husband's manuscripts and letters. Consuela then drinks a potion and then faints, and when Sergio attempts to call an ambulance he is distracted by the entrance of Aura, a beautiful young woman who says she is Consuela's daughter. After the two put Consuela to bed they begin to talk, and Sergio falls madly in love with her and decides to take the job. After a series of bizarre incidents, in which we slowly learn that Aura and Consuela only appear to move when the other is still, Sergio meets his rival, Fabrizio, whom he has apparently been hired to replace. Fabrizio, nearly mad, is also in love with Aura. The two men fight, and Sergio accidentally kills Fabrizio. This means, of course, that Consuela has Sergio entirely under her control, as she can turn him into the police at any time.
As the figures of the beautiful Aura and elderly Consuela blend together, Sergio ultimately tries to force them apart, yelling at the old woman who he again assumes is spying on him. Although Aura appears to be in love with him, so does Consuela. As the reality of the situation dawns on him, Sergio discovers that he is utterly dependent on Consuela to provide him with Aura, the woman he loves. After awhile though, both Consuela and Aura seem to tire of him, and he discovers that he is being replaced with a new, younger, man. Realizing what is happening, Sergio burns Consuela and escapes.
The original short story this is based on was filled with heretical imagery and a smart blending of the succubi/witch myths and seemed almost ready-made for a motion picture adaptation. It's a shame that the director has done such a poor job with it. Although much of the original plot remains the same, the first half of the movie version feels very much like an ordinary rumination on the battle of the sexes. By the time things do get interesting, the plot has dragged on so much that the viewer will have already guessed the story's twist. The heretical symbolism from the short story has been removed, as has much of the more interesting elements of the Consuela/Aura doppelganger effect.
What is interesting is the unique take on the witch mythos is different. Woman makes man fall in love with her, breaks him to the point where he is utterly dependent on her, and then bores of him and finds another, pitting the two men against each other. We can see perhaps part of the basis for the fear of witches is the attack they represent on the traditional male power in society. Here, sorcery is a set of blue balls.