This is probably a hint that Shanks is a Celestial Dragon.
In the scene where he defeats the nearby boss, Luffy uses his technique for the first time.
I predict that he will defeat Im-sama, who has turned into a dragon, in a self-homage to this scene.
And it’s a pistol, as expected.
The final blow is a pistol in this work.
“My punch is as strong as a pistol.”
This is important.
In fact, in One Piece,
pistols are always used in murder scenes, except for execution scenes.
Killing is not done with the powers of Devil Fruits.
Aren’t you surprised?