In Act 1 Scene 1, before you meet him, you learn that he met Macdonwald in battle and "unseam'd him from the nave to the chops and fix'd his head on our battlements."
Lady Macbeth
The line "what's done, is done" is spoken by Lady Macbeth in the play Macbeth.
the quotation from Shakespears Macbeth is "if it were done when 'tis done, then 'twer well it 'twer done quickly" (Macbeth, act 1 scene 7)
in a letter
kills Macbeth
I'm guessing that you are asking two questions: "How does Malcolm feel about Macbeth?" and "What has Macbeth done to become the king?" The answer to the second question is simple: Macbeth killed King Duncan in order to become king. The answer to the first question is almost as simple: Malcolm hates and fears Macbeth. I hope your command of English is sufficient to understand this answer.
Drugged them.
Her part is decisive. If you read or watch Act 1 Scene 7 you will know that Macbeth, left on his own, decided not to commit the murder. He says "We shall proceed no further in this business." Lady Macbeth then proceeds to change his mind, at least for long enough that the deed gets done. She appeals to his irrational emotions, when his decision not to commit the murder was based on reason and logic, as shown in Macbeth's speech, "If it were done when 'tis done, then 'twere well it were done quickly."
Lady Macbeth's statement "What is done is done" is ironic because she says it to try to reassure herself and her husband after Duncan's murder, when in reality, the consequences of their actions continue to haunt them throughout the play. The statement reflects Lady Macbeth's attempts to suppress her guilt and anxiety by dismissing the gravity of their crimes, which ultimately leads to their downfall.
The crucial part. Without Lady Macbeth, this would have been Macbeth's final decision: "We will proceed no further in this business." Macbeth would never have killed Duncan unless Lady Macbeth had goaded him into it.
Lady Macbeth is telling Macbeth to grow up and just kill the King. But Lady Macbeth tells Macbeth that she cant kill him since he looks like her father, this shows the reader that Lady Macbeth isn't as crazy as we think she is.
he is gay