The Wire - season 5 finale question

[barcelonic29]

At the end of the season 5 finale, Marlo leaves the fundraiser dressed in his suit and goes to one of his old corners and says "Do you know who I am?", then one of the dealers tries to shoot him but he knocks away the gun and stays on the corner as the dealers run off, smiling.

Why does he do that?

I have two theories... one - he has decided he wants to be a gangster after all and not a legit businessman. two - he wanted to correct his reputation before he goes, because Omar had been calling for him to fight him face to face but nobody told Marlo so he never knew (referencing the scene when Marlo is in jail talking to Chris and Cheese).

Does anyone know why this was, or have any thoughts on it?