Brutus again reassures Cassius of his opinion regarding Mark Antony when he says, "Alas, good Cassius, do not think of him. If he love Caesar, all that he can do is to himself -- take thought and die for Caesar. And that were much he should, for he is given to sports, to wildness, and much company" (2.1.185-189). Antony's love of partying is pointed out again when Caesar comments in surprise that Antony is up early, but yet in defense of his careless behavior when he says, "See! Antony, that revels long a-nights, Is notwithstanding up. Good Morrow, Antony" (2.2.115-116). Caesar supported Antony 's behavior because he felt Antony's sincerity towards him.
Antony was distressed by Caesar's death. He felt his loyalty to Caesar must continue in his duty to carry on Caesar's reign and clear his name. Therefore, he first cunningly made peace with the conspirators by sending his servant to ask them for his safe passage and an explanation for Caesar's death. Brutus, being the magnanimous character that he is, gave him both. Antony then convinced them that he was on their side by shaking their bloody hands, to show them he was together with them in their conspiracy.
However, once Antony is left on his own on stage, we see his feelings of guilt towards his behavior; his love for Caesar, as well as his own plot to make sure all hell will soon break loose in order to avenge the death of Caesar (3.1.263-276).
Antony's "true colors" begin to surface as his speech in Act 3, Scene 2 cunningly and cleverly manipulates the people to do what he wanted to do when he first met with the conspirators, but wasn't able to do himself. He starts by appealing to the audience and implying strongly that Caesar paid more than his due (3.2.75-81). His Machiavellian scheming side is brought forth in his use of reverse psychology, when he first pretends to respect the conspirators calling them honorable men, and then slowly adding in things to prove that they are not. His sarcasm increases as he tried to prompt a response from his audience, "I will not do them wrong; I rather choose To wrong the dead, to wrong myself and you, Than I will wrong such honorable men" (3.2.126-128). Antony here, is trying in repetitive rhetoric to mock the idea of honor that Brutus has created so that he can bring the masses to side with him. "I fear I wrong the honorable men Whose daggers have stabbed Caesar; I do fear it" (3.2.152-154). Finally he incites the response from the people that he has been waiting for, "They were traitors: honorable men!" (3.2.155)
He teases the people with the will, waving it in the air and bringing it up over and over again, yet pretending as if he was not going to read it. This causes the people to condemn Brutus and the rest of the conspirators like Antony had planned. Surely these are the workings of a ruthless mind that has been intoxicated by the idea of vengeance, especially if this vengeance will work in his favour to grant him power. Antony believes that if he can take control while the state is in such turmoil, he will remain in power. Here again, we see the personality of an opportunist.
Antony lives up to the Machiavellian schemer's portrayal by clearly appealing to the crowds basic emotions. He uses tactics like descending from the platform to stand amongst the people to make them feel like he is one of them. He also literally exposes Caesar's wounds to them to further emphasise his point (3.2.196-197). He also acts humbled by the crowd's attentive nature, (3.2.217-229) in turn making them feel guilty.
He is crafty and sly, but he speaks with conviction and that sways the masses to his side. Once the crowd is passionately fired up and Antony has recklessly unleashed the "dogs of war" over Rome, he fuels them further, and then states deviously, "Mischief, thou art afoot, Take thou what course thou wilt" (3.2.260-261). Then, as if there were no sentiments involved, he turns immediately to his business with Octavius.
When we see Antony soon after, his callousness is reflected in his reference to the people who have to be killed, "These many then shall die; their names are pricked" (4.1.1). The fact that he feels nothing to determine a person's fate when "pricking" their name reflects his cold, inhumane approach to power. He is completely absorbed in the current important position he holds, that it does not matter what people must die for him to maintain it. This point is reiterated when Lepidus submissively agrees to Octavius' suggestion that his brother must be killed. Lepidus then suggests that Antony's nephew Publius must die. Antony's only response to this is, "He shall not live; look, with a spot I damn him" (4.1.6). He feels powerful that he can "damn" someone to their death, and this seems to negate any need he should have to acknowledge any sort of responsibility for it.
Antony's reformation into a cold-hearted, ruthless leader is further proven with his intention to undermine the content in Caesar's will which he previously used to instigate sympathy for Caesar amongst the people (3.2. 240-252). Now he says almost matter-of-factly, "Fetch the will hither, and we shall determine How to cut off some charge in legacies" (4.1.8-9).
His brutal ways continue when he goes against Lepidus behind his back, telling Octavius that Lepidus is unworthy to share their power. Antony describes him in an exceedingly derogatory manner, "This is a slight unmeritable man, Meet to be sent on errands: is it fit" (4.1.12-13). When Octavius tries to put it fairly by saying that Lepidus is a "tried and valiant soldier" (4.1.29), Antony compares those fine traits of Lepidus' to Antony's own horse "So is my horse, Octavius, and for that I do appoint him store of provender" (4.1.29-30). Antony has clearly a lack of compassion common to any manipulative leader or Machiavellian schemer, as shown in his attitude towards pricking the names of the people who were fated to die as well as here.
Antony's final words about Brutus at his death, "This was the noblest Roman of them all…'This was the man!'" (5.5.68-75) might give us reason to believe that Antony might possibly carry the ability to recognize good from bad. However, it doesn't help change the image of Antony as a forceful political opportunist who would use any passage open to him, including the murder of a friend, to further his political ambition.