How does the characterization of Caesar in this passage connect to the central idea of the passage?

By reflecting on Caesar’s position in society, Brutus comes to realize that Caesar has lost integrity as a ruler and that he must join the plot to assassinate Caesar.
When Brutus allows himself to be convinced to join the conspiracy against Caesar, it seals his fate and leads to his ultimate defeat and death.
Brutus decides to join the conspiracy against Caesar because he fears that Caesar will become ruthless once he has absolute power.
Brutus decides that he must prevent Caesar from becoming ruthless as a result of having absolute power, but in the end it is Brutus who is corrupted by power.