There are a few subtle details and references to the main story ...

Mini Gear 4 is one of Luffy’s newest, yet already overlooked transformations. Luffy first uses this quite recently, in One ...

This means Luffy hasn't hit his strongest transformation yet, and it is something that he's going to officially use when he learns to damage immortals in the Elbaf arc. Oda has already set up a major ...

Luffy has faced villains that ought to end his journey, but he always survives the face-off because of his willpower.