Who Is Responsible Of The Demise Of The Central Characters In Macbeth?

In the play Macbeth by Shakespeare, it is shown that there are deep character flaws and it shows how one thing leads to another. Macbeth follows the path of a tragedy as described by Aristotle, where a tragic hero is someone who falls off great heights because of an essential flaw within him/her. The witches seem to have been the main cause of demise of the central characters.
There are many characters that lead to the downfall of Macbeth but mainly two come in mind when thinking of such, being Lady Macbeth and the witches. The role of Lady Macbeth is to be an ambitious wife who wants nothing but power, whereas the role of the witches is to foretell what is going to happen. Once the witches tell Macbeth that he is going to be announced Thane of Cawdor, and it happens straight after, he also believes that he is supposed to be king as told by the witches. We also need to see about the beliefs in those times, where superstition was widely believed and all the supernatural was taken into account. Lady Macbeth believed the witches straight off and due to her ambition convinced Macbeth into killing Duncan which started the downfall.
We can say that Macbeth’s ambition led him to his own demise but there would have to have been someone behind his ambition to make him go through with it; as we can see in Act 1, after the witches tell him that he is to be announced king, Lady Macbeth basically forces him to go and kill King Duncan; after murdering the king, he feels uncomfortable and says “To know my deed, ‘twere best not to know myself” (Act 2, scene 2). Knowing that he had committed such an act it would be difficult to act innocent and not know of what had happened. Once announced King, Macbeth goes on a frenzy to kill anyone who can be a threat to him; by first killing Banquo, his best friend, then going and killing Macduff’s whole family. Macbeth was showing that due to ambition he was becoming a monster and went to the witches to know some more of what was going to...