I've been looking into the fighting styles in this manga. We know in most mangas, there's only 1 thing that everyone in the planet is susceptible/required to learn to be strong/above-and-beyond (chakra, nen, ki, innocences, alchemy, plant/angel, notebook, etc..), but One Piece is different.
Oda has Devil Fruits, but that's not everything. You have blades/swords, which at high levels can do some pretty crazy things. Hyponotisism which hasn't been used too much is also something else. Then there's CP9's 6forms. You have dials too. Also guns and projectiles. Oh ya, and mer-men got some pretty crazy stuff too. But even that doesn't outmatch normal people who just strengthen their bodies via kicking/punching.
But I was curious about one more, that I thought was pretty new but didn't get built on too much. And that is Kumadori's technique. Does anyone else thing his Life Restore tech is a build towards something bigger, a one time thing, or I just read it wrong?