This is more of a betting battle, for from the looks of it, ITS ABOUT TO GO DOWN!!!!
Most likely it will be Zoro vs Fujitora and Luffy vs Doflamingo. They're already set on the path of crushing the bird guy but for some reason I'm sure we'll find out Issoh is helping him. And that means it's gonna be ONE. EPIC. BATTLE. or two I guess lol BUT YOU KNOW WHAT I MEAN.
Battle is in Dressrosa of course!