What is the character of Mark Anthony as revealed in Acts 3 and 4 of "Julius Caesar"?

Marc Antony, who is part of the "train" of Caesar as he victoriously enters the city of Rome in Act I, is obviously a follower of Julius Caesar.  Immediatedly after the assassination, Antony indicates this devotion to his friend and ruler as he tells Brutus,

Now, whilst your purpled hands do reek and smoke,/Fulfill your pleasure.  Live a thousand years,/I shall not find myself so apt to die;/No place will please me so, no mean of death,/As here by Caesar, and by you cut off,/The choice and master spirits of this age. (III,i,158-163)

That he is clever as well as devoted is hinted at here.  For, Antony has responded in this manner after hearing Brutus's greeting of "Welcome,"(III,i,157), and he is aware of the principled, noble nature of Brutus.  He, perhaps, gambles that Brutus will not have him killed.

At any rate, when he is not slain, Antony realizes that he wields influence and that, as Cassius as earlier remarked in the play, "Men at some time are masters of their fates" (I,ii, 139) and may be able to change the course of events Thus, in his funeral oration, his fierce love for Caesar over devotion to Rome is revealed in the character of Antony as over Caesar's dead body, Antony begs Caesar for "pardon" that he has been "meek and gentle with these butchers!" (III,i,255).  He promises that

Domestic fury and fierce civil strife/Shall cumber all the parts of Italy;/Bood and destruction shall be so in use,...And Caesar's spirit, ranging for revenge,...That this foul deed shall smell above the earth/With carrion men, groaning for burial. (III,i,262-275)

It is doubtful that Caesar would have wanted his beloved Rome thrown into such turmoil at his death.  However, Antony is bent upon this plan of revenge, for with his rhetorical skills, he upsets the crowd and turns them against Brutus and the other conspirators.  Then, in Act IV, his manipulative power is also evident as he and Octavius and Lepidus in the "proscription scene" make a list of Romans who will be killed or executed.  Antony is willing to trade the life of his nephew to further his military plans, declaring,

This is a slight unmeritable man,/Meet to be sent on errands; is it fit,/The threefold world divided, he should stand/One of the three to share it? (IV,i,12-15)

While Marc Antony displays a deep love and devotion for Caesar his motives in seeking revenge and power seem much too personal and ignoble.  Later, in Act V as he eulogizes Brutus, Antony seems depicted in a less self-serving and cruel manner as he praises "the noblest Roman of all" (V,v,68).