"Well!" resumed Madame Cheron, "you have not given me the promise, though, that I demand." (1.12.33)
Oh, Madame Cheron, you smarty-pants. There's no way Em's going to break her word to her aunt, even if she's totally head-over-heels in love with Valancourt.
Emily observed with concern the ascendancy, which Montoni had acquired over Madame Cheron […] (1.13.3)
Em's got eyes, and she sees how the master manipulator is getting manipulated. But why doesn't she ever consider that Madame Cheron's pulling the wool over Montoni's eyes?
"Stay!" said Valancourt. "I conjure you stay, for I have much to tell you." (1.13.50)
Sorry, Valancourt, all your persuasive powers won't get Em to do a thing she doesn't want to do. If Em's really in love with Valancourt, why is she immune to all his manipulations?
Montoni, who had been often at Turin, and cared little about views of any kind, did not comply with his wife's request, that they might survey some of the palaces […] (2.2.3)
This is one of those little moments that's indicative of something huge. After manipulating Madame Cheron into marriage, Montoni doesn't bother indulging her as often.
"You shall be witness," said she, "of my opposition. Now, sir, repeat the command, I have so often refused to obey." (2.7.14)
Two can play this game. Montoni's doing his best to bend his wife to his will, but she's got an ally in Emily.
He blamed himself, that he had not urged these more forcibly to her, while it might be in his power to detain her […] (2.8.1)
You might think these sketchy words were spoken by Montoni… and that's incorrect. Valancourt's inability to manipulate Em is a real problem in his eyes.
"Send away the girl," said he, "and I will tell you more." (2.12.59)
Oooh, Barnardine is good. He knows that the key to getting Em to do what he wants is to separate her from loudmouth Annette.
"All that is required of you will be to sign your name to this paper." (3.5.9)
Even though Em figures out Montoni's game pretty quickly, she's no match for his quick wits and ruthlessness. As soon as one strategy fails, he's on to the next one.
"O! you do pity me, then, you do love me! Yes, you are still my own Emily—let me believe those tears, that tell me so!" (4.1.7)
Valancourt is up to his old tricks again. It's hard to believe he wants what's best for Em when he keeps trying to push her buttons.
The artful Italian soon perceived, that she had regained her influence over him, and, soothed by the discovery, she determined to live, and to employ all her enchantments to win his consent to the diabolical deed […] (4.18.12)
Signora Laurentini may just be even more skilled at manipulating people than Montoni. If the narrator's to be believed, she succeeded in goading a man in love into murdering his wife.