Answer:
Macbeth himself, Lady Macbeth and three witches are to be blamed for Macbeth’s downfall.
Step-by-step explanation:
The three witches predicted that “Macbeth” will be the King of Scotland. Thereafter, Macbeth started becoming thirsty for power.
Macbeth was not a wise man and got convinced by his wife, after she called him a coward, to murder Duncan. Macbeth even killed Banquo who was his best friend. So, he is responsible for his acts.
He did all this only because he wanted the power of being a king. Though eventually he was skeptical about Duncan's murder, he got convinced by his wife to murder Duncan. Thus, both the witches and 'Lady Macbeth' are liable for his downfall.