How has Macbeth's character developed from Act 2, Scene 2, to the Banquet Scene?

In the second scene of Act II, Macbeth has just murdered King Duncan. While Lady Macbeth seems calm, he starts. He thinks he hears someone cry out, or he simply hears men talking in their sleep. Macbeth is terrified of his act:

“I am afraid to think what I have done; / Look on't again I dare not.”

Even though he was reluctant to commit this crime, Macbeth feigns shock at the discovery of Duncan’s...

In the second scene of Act II, Macbeth has just murdered King Duncan. While Lady Macbeth seems calm, he starts. He thinks he hears someone cry out, or he simply hears men talking in their sleep. Macbeth is terrified of his act:

“I am afraid to think what I have done; / Look on't again I dare not.”

Even though he was reluctant to commit this crime, Macbeth feigns shock at the discovery of Duncan’s body. Moreover, he kills the guards whom he framed for the murder. He becomes increasingly paranoid and dissatisfied, worrying about his uncertain position as king: “We have scotch'd the snake, not kill'd it.” Macbeth thinks it necessary to kill his friend Banquo and Banquo’s son Fleance because the witches predicted that Banquo’s “children shall be kings.” He also becomes increasingly manipulative, convincing two men to murder Banquo and Fleance. In addition, though he and Lady Macbeth had been so close, Macbeth plays things closer to his chest, telling her to “Be innocent of the knowledge” of how he will deal with Banquo.

During the banquet scene, Macbeth tries to put on a good face, but he is distracted by news of Banquo’s death and Fleance’s survival. He even condemns Banquo for not making it to the feast. However, the hallucinations that have plagued him since he thought he saw a dagger pointing the way towards Duncan explode in this scene. Macbeth is convinced that Banquo’s ghost has joined them, and his ravings nearly give him away. Eventually, Lady Macbeth needs to send everyone home. Between the second act and the end of the fourth act, Macbeth has committed more murders and has become more callous and unsettled.