Discuss Marc Antony's character in Julius Caesar.

Yeah, he is manipulative but Anthony is pure at heart. He only designs a plan to bring out the conspirators' real reasons for murdering Caesar. It is not debatable that he loved Caesar. Yes, I do wonder why he sent a servant to um, demand? an assurance that he will be safe before entering the crime scene when later he tells them that if they were to kill him now, at this place or time "so apt" to die, with the "instrument" which killed Caesar, he will be most honored. He fears for his life. So what? Sue the guy.
Apart from that, Antony seems to be a I'm-a-good-man-but-if-you-kill-my-best-friend-i'll-take-my-sweet-revenge kind of guy. He's clever, very. Sharp, shrewd, knows when to play his cards. and then, he does stir the crowd up to a mutiny, even after repeatedly saying that’s not what he intends...
So all in all, he's not exactly noble, but when he promises Brutus to not speak ill of them, he keeps it, by twisting his words and implying things. Rhetorical questions, things like that. So he is clever/ scheming. Manipulative. But a good friend. And hell, that's what matter, right?