I’ve seen a lot of hate with the last chapter, but so far it fits everything Oda’s been doing.
NARRATIVELY
There are probably other reasons Oda is doing this, but right now there’s a clear and obvious justification for Bonney’s transformation. It’s to show that power in One Piece relates directly to belief. Saturn explicitly said Bonney’s power is lower when she understands “reality.” This is the world that the World Government has built, one with no room for dreaming/desires because having strong dreams/desires is literally how people become powerful in the series. Haki is the will to make your dreams come true manifest in reality. Devil Fruit powers are based on beliefs. The more creative you are with your powers, the stronger you are.
Bonney’s here to show us that when you don’t limit yourself to narrow definition of what’s possible created by an authoritarian government, you have the strength to oppose them and that Nika can inspire people to fight against them. This is their worst nightmare because it’s the only thing that can stop them from ruling.
POWER-WISE
Bonney has explicitly stated that her distorted future ability only works briefly and exhausts her quickly. This really isn’t any different than the first time Luffy used Gear 3.
When Bonney turned into “Gear 3”, she was not proficient in punching with her distorted future ability.
Luffy has spent over a decade as a rubber man. Luffy has absolutely mastered his body. Luffy is a physical monster. Luffy has skill with his power. Bonney does not have this level of training or skill.
IN SUMMARY
This point here is showing Bonney’s potential. She still needs to master this ability for it to be anything beyond a quick gimmick. Luffy’s presence has made her, and a lot of people stronger. Without Luffy she would not have gotten this powerup, and it’s very likely she’s not going to come close to the power of other characters.
Luffy is still special because he is the person who did this. Bonney’s like a kid wearing a Superman costume. It is a facsimile of Luffy meant to represent what happens if you throw away the narrative the World Government has created through oppression.
Luffy is the protagonist because everyone’s going to unlock their own potentials because they believe they can do the impossible. This is just a very literal way of showing it because it completely contradicts what Saturn said.
*by the_idiotlord
