As Luffy bursts in laughter, Pica snaps and raises his arm to throw a punch.
Marines and Donquixote family members all run away as Pica's punch is equivalent of a city falling on them
Zoro tells Luffy to stop teasing the enemy, but he himself bursts out in laughter as well
The massive punch lands. Each finger larger than a building, the punch destroys a portion of the city and sends everyone flying.
Luffy and Zoro (and Law) land in the square near the Colisseum. Zoro has no idea how to defeat a stone giant larger than the size of Oars.
The trio meets Cavendish. Caven immediately attacks Law for being a "Worst Generation", but Luffy stops him.
He tells him he's one of his friends now, and Caven nods and tells him he will not go after any Strawhats. He owes his life to God Usopp.
Caven offers to take Doflamingo's head to return the favor, but Luffy refuses, saying that's his job.
Caven is upset Luffy is trying to become "more popular". He then fantasizes what would happen if he takes the head of Doflamingo and becomes super star, but Luffy doesn't have time for this, and leaves taking Zoro and Law with him. (Cavendish doesn't notice, of course)