The Antony we saw earlier was heartbroken. He was totally concerned with avenging Caesar's death.
Antony seems to have changed. He seems to be driven by power himself. He talks about dividng the power of the world in three positions. Then he states that Ledipus is a jackass and is not fit to reign with him.
He is insulting and cold. He appears to have changed into someone who once was against the conspirators into someone who is concerned with power and ruling.
Antony who earlier shared with the people how Caesar had left them in his will now is concerned with how he can reduce what the people will get.
It is clear that Antony is more about gaining power than avenging Caesar's death. He has come to enjoy power. He is driven by gaining power. He is now not willing to divide the power three ways. He belittles Ledipus.
Antony is making a list of who will die. Some on the list are relatives.