His perceptions had changed and what once had been a gentle aroma and atmosphere around the castle had turned into a thick and bloody stench. He had turned the situation into a royal blood bath, and had brought all of his friends into the issue along with him. Macbeth and Duncan were once very close friends, but Macbeth's desires had lowered himself as a man to such a low level, that it would only be a matter of time before the guilt would surely arise from the depths of his inner soul. Macbeth had betrayed Duncan and all his trust and faith that he had put towards Macbeth as being General of the Army, and even more, all of his other compassionate and loving friends that he also once had. It was because of his eagerness and his want for power and strength that had overtaken him. He had not thought out his plans, and as a result, he had made everyone dislike him for who he was as a man, and as a Thane.
Macbeth and Banquo had once used to be very close friends that were literally inseparable and Macbeth would have absolutely done anything for Banquo, and vice versa. Macbeth had now placed himself in a situation that would be just utterly be impossible to get out of. It was completely his fault and because of his dark and evil intentions being so full of greed and power, he has now messed up his life along with friends he used to love, treasure, and cherish. The desire for power can conflict between two very close friends and once this takes place, a friendship that had once thought that would have lasted for eternity, would be torn and shredded into two miniature pieces. Macbeth knew that it was going to be much easier killing Banquo as it was to kill Duncan because of the decline in the pressure and since Macbeth had put himself into a situation where his hands had already shed the blood of Duncan, he really had nothing to lose. The first time would always be the hardest, but once again, Macbeth had shown his vulnerability.