Vonnegut thinks that climactic end of the book with Derby's shooting would be ironical since Elgar was a kind and just man who did not deserved to die.
Explanation:
The Slaughterhouse-Five storyline revolves amidst world war and its climactic endings. In the story, a strong emphasis has been put on Tralfamadorian philosophy. With the death of each of the phrase “So it goes” appears meaning the relative presence of a person in a moment and absence in another.
Hence, in the story Vonnegut not only dismisses the conventional climactic story structure which would probably end in the shooting of Elgar Derby who was otherwise a kind and just man. He was to receive the punishment for a petty mistake of being caught with a teapot. However, the destiny prevails and “so it goes” meaning that Justice does not prevail in death.
When Macbeth hears that Fleance has escaped the murderers, he reacts with anxiety. When Macbeth begins talking to Banquo's ghost, lady Macbeth reacts by telling the others Macbeth has an illness
a figure of speech involving the comparison of one thing with another thing of a different kind, used to make a description more emphatic or vivid (e.g., as brave as a lion, crazy like a fox ).
