1. Rowan previously learnt how to bounce on the air like Geppo. How?
- His ability, as previously explained, allows him to generate a vector from himself and the solid objects he touches spontaneously, which bypasses the Newton's 3rd law of motion. The generated vector's direction is always set: perpendicular to the surface where it is generated from. This vector is what I call 'bounce.'
- Why can we walk on the solid ground, but not on the air? Because air is a gas molecule in terms of the state of matter, it has much more entropy than solid, and due to its wild movements, each molecule is unable to maintain a shape and produce a regular structure. What Rowan essentially did is to ignore that by a large margin. The bounce generated from his feet were so great in terms of magnitude and quick in speed, that it allowed Rowan to propel while on the air by bouncing off of each gas molecule. Again, this is unrealistic and doesn't make sense, but it's One Piece world.
- Point is, if he can do this to fly, he can do the same to attack. This is first shown when Rowan visits Syrup village; he creates a dent on the cliff without touching it. His bounce force excites the air molecules so much, and this energy gets passed on from molecule to molecule through collision. Although the force is lost as it continues to travel, Rowan's bounce force was enough to generate an incredible amount of damage.
- So how does his bounce generate an incredible amount of force in the first place? If you recall, his muscles became so dense that his bodyweight far surpassed that of a normal person. Imagine him trying to carry such weight on the air. Yeah, you need lots of force to keep him afloat. Rowan was already used to expelling large amount of force since he learnt to bounce off of the air.
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2. Now this is the main point, how did Rowan hit Smoker?
- Now we know that Rowan's vector (bounce) can excite and affect the gas molecules. Wait a minute, doesn't Smoker's Smoke Smoke fruit allow him to turn into smoke, which is a gas? Yes, of course! The important point is that he turns into gas. Rowan can excite the gas molecules but use bounce forces at incredible strength. In other words, Rowan already learnt how to hit Smoker prior to facing him. Additionally, Smoker's smoke is denser than the air; hitting Smoker is easier than bouncing off of the air. And hence, Smoker, who relied heavily on his fruit, was utterly defeated by Rowan.
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3. If that's the case, isn't Rowan technically invincible? He'd be able to hit everything!
- Just reading this, you might think that Bounce Bounce fruit is overpowered. But hey, there are couple of key points that you got to keep in mind.
- First, it has been mentioned that the bounce force Rowan can generate depends on his physical strength. Rowan's physical prowess, as stated in auxiliary, already reached at the level of Rear Admiral. Which means, if someone like Garp comes and punches Rowan, he's done for.
- Second, dense gases like smoke and poison gas (Caesar), Rowan can hit without haki, however, not pure energies or subatomic particles such as fire, light, lightning, darkness, gravity, etc. Bounce Bounce fruit is purely physical.
- Third, the vector (bounce) generated from Rowan is always uni-directional. If his attack through bounce is a large scale, it isn't because he's able to produce something big like that, but it's more like 8 balls, where you use one white ball (vector) to hit all balls (molecules) simultaneously.
- Last, as for the natural counter for Bounce Bounce fruit, there are mainly two of them: Tremor Tremor fruit and Hollow Hollow fruit.
- Tremor Tremor fruit: the vibration created from the fruit completely nullifies the vector generated by Bounce. If vector travels in x-axis, the vibration from this fruit not only weakens the magnitude, but applies force in all kinds of directions, that the vector itself loses its original intention.
- Hollow Hollow fruit: immune to all physical attacks. Enough said.
Ughh, my head hurts writing this. Of course, most of this is BS but I hope I clarified some confusions here.