[Spoilers] If it is..

[Kiiszame]

If it is Sabo then he must be wanting some payback for not being there for Ace at the war. He does feel guilty as he mentions it to Koala.
I mean he is going to get a chance to fight Burgess the 2nd fleet commander of black beard who was the reason Ace got captured. Sabo will pwn I hope! Also get some payback for Ace.

 

[Sir Blades]

I'm dying to see Sabo's fighting style.

 

[Fireplay]

Sabo will own these fools.