1) How does Malcolm use irony to test Macduff's allegiance? Malcolm used irony to test Macduff's allegiances with a false confession. In order to see if Macduff is trustworthy or not, Malcolm claims that he is lustful, greedy, and devoid of any qualities that the king possesses. Because Malcolm is a righteous character, this is presented as ironic because Malcolm is acting the opposite of his true personality.
2) Blood is a symbol throughout