This scene starts to characterise Macbeth's bipolarity, he begins to feel his closest companion is untrustworthy. Thus, lying about the way he feels about his destiny.
The pressure of the prophecies builds on Macbeth and Banquo. This forces Macbeth to give an irrational opinion on them. Macbeth slowly loses his trust in Banquo. This forces a change in the plot.
I had a dream last night about the three witches. At least part of what they said about you was true.
Macbeth's characterisation of being a weak & sympathetic ruler is shown. This again questions his ability to be tyrant or king. He also does not want to be inferior to Lady Macbeth.
Following the pressure, Macbeth hallucinates. A dagger and the plot to kill Duncan appears. Macbeth drowns in the feeling of guilt. He is forced to murder the king solely because of Lady Macbeth.
This scene characterises Lady Macbeth as a powerful leader. She is one of the most powerful female characters in all of literature. Unlike Macbeth, she lacks all humanity, and will to forgive.
After killing Duncan, Macbeth is distraught. In spite of the moment, Macbeth has brought back the murder weapon. This infuriates Lady Macbeth. She is forced to bring it back herself.
Mcduff rings the bell to wake the rest of the noblemen. During this time, Macbeth has gone to Duncan's room and murdered all the guards. He claims it was out of rage. Lady Macbeth faints after hearing the news.
In this scene, Macbeth is guilt tripping to prevent being accused of murder and treason. He has killed the King as well as the guards. This characterises his 'manly' nature, "out of rage". He may have done so to prove Lady Macbeth wrong.
If I had only died an hour before this event I could say I had lived a blessed life. Because from this moment on, there is nothing worth living for.
Malcolm and Donalbain leave the city in hopes of being accused of the crimes. This act only makes the town more suspicious.
In this scene, Macbeth is characterised as a sly, culpable and selfish leader. His acts may only come to haunt him later in the play. Overall, Macbeth's characterisation is based off proving others wrong and the greed for power.
Macbeth is crowned King, Thane of Glamis, Thane of Cawdor. However, the witches prophecies have failed. Macbeth has twisted fate and falsely become royalty to prove Lady Macbeth wrong, as well as his self-esteem being boosted by the witches.