User blog comment:Hustleshine/Who's Shichibukai?/@comment-3125914-20120208155524

Considering that Law became a Shichibukai during the time skip, he might have had a fight that guy and used his ability to cut him in two. The top part must be somewhere lost in Punk Hazard.

If the topless guy is Buggy, he might have gotten taller a lot during the time skip. But I doubt it's him because he doesn't talk like that and he should have recognized Luffy's voice.

If Doflamingo cut him, he would be dead. Unless he has some sort of devil fruit that keeps him alive. Or there are some secrets to Doflamingo's ability that will be revealed.