Luffy doesn't usually kill his enemies but Doffy seems like he might make an exception. First of all i am of the belief that Doffy will die for a couple reasons such as..
Law has wanted to kill him for forever and whether or not Law is 100% or even 10% i could see him striking Doffy down after Luffy defeats him.
Doffy has the most insane endurance of any character in One Piece ever but if you get gamma knifed and all you do is first aid you gonna die period. It just depends on when he dies.
Another reason that i have is if Doffy can just blackmail the WG how can they keep him? I mean, knowing Doffy he has some contingency for when the WG came and took him away. So if he gets thrown in ID then his plan would swing into effect and he would get out agian. So the only way i can think of that he doesn't pop back up is of he dies.
Also just to throw a random theory of mine in.... I think Burgess is gonna take the Ito Ito no mi after Luffy defeats Doffy or Law kills him. This is mainly becuase if Burgess leaves empty handed with his tail between his legs i don't reallly see what the point was of bringing him in and the Ito Ito no mi is one of the strongest fruits we know of so.... it kinda makes sense.
So after this huge arc do you guys think that the climax will be the the death of Doffy or do you think otherwise? Any holes in my theories that you want to bash on?