Simile, because its comparing with "as"
The magical power of the three witch sisters in Macbeth is decisive for the progress of this one, which is one of their best pieces. Macbeth, the protagonist, ascends the throne of Scotland thanks to a series of crimes and intrigues, but at all times guided by supernatural forces. It is the witches who, like the three Moira sisters of Greek mythology, decide the future of the characters.
Macbeth seeks his luck, launched by the three witches. Shakespeare's character follows the witches' prophecy into the future. He seeks, at all times, the words of the three sisters to the point of overcoming them. An example of this overtaking can be seen in the fact that Malcom, the son of Duncan, is crowned, and not Fleance, the son of Banquo, as mentioned in the witches' sentence. This fact should suggest to us that this prophetic speech was not so certain and / or that, in part, they were supplanted by the interpretative will that covers the action of the main character. Therefore, Macbeth built part of his tragedy, in that he chose to interpret such prophecies.
