Now here’s an interesting prospect because bullets don’t hurt Luffy. Now for all of you guys who read most of Black Cat you probably think he’s nothing without his gun. Well you should have read the last volume. He got te super rail gun which would probably take Luffy out with one move. Train also has hand to hand skills.
Update 8 7 2020 I’m afraid Luffy will prove to be too fast here. Luffy wins.