If there's one thing consistent in One Piece, it's how Luffy has continuously pushed the boundaries of his abilities, with Gear 4 serving as one of his most powerful transformations (second only ...

Luffy's attacks have changed greatly as One Piece has gone on. Here's a closer look at how much they've changed.

and ended up creating Gear 4, which works on the concept of inflating muscles, as Luffy calls it muscle balloon. By inflating his muscles and gaining a bulky form, Luffy can demolish his enemies ...