Shakespeare uses Banquo as a character foil to Macbeth. While Macbeth is rash and obsessive, Banquo is measured and wise. Macduff is also an effective foil to Macbeth. Macduff personifies the traits of loyalty and the limits of loyalty. Macduff seeks to serve a righteous leader while Macbeth is only concerned about his own ambition and power. L. Macbeth certainly uses manipulation to expose Macbeth's early flaws.