Macbeth is characterized as a greedy man who will stop at nothing short of murder to get what he wants. Although he is greedy, he does think twice about murdering Duncan. After his wife, Lady Macbeth, challenges his manhood, he gives in to her manipulation and proceeds to murder Duncan.
Macbeth desires to be king after hearing the witches prophesy about it. A seed is planted in him and he goes after the throne through murderous deeds.
Of course, Banquo heard the witches prophecy; therefore , Banquo must die according to Macbeth. Again, he is responsible for another murder. Macbeth killed or had Macduff's family killed because the witches had told Macbeth to beware of Macduff. He killed or had someone kill Macduff's wife and children so Macduff would not have an heir. Again, Macbeth proves to be a cold-blooded murderer. He is in a murdering frenzy. He is power hungry and his way of thinking is deranged.
Actually, he does begin to see visions and hallucinations. It appears that Macbeth is losing his mind.