Now onto the Post Wano landscape. Here I am predicting quite a few things so while my outline of this arc may not be completely correct I think the larger points are clear. We have never had an instance in which Luffy’s bounty did not become (at the bare minimum) 125% of what his main enemy’s bounty was at the beginning of the arc. This alone should stand to reason that Luffy’s bounty will be higher than Kaido’s but I do understand some of your reservations. However, defeating a Yonko is clearly the largest accomplishment the Straw Hats have ever achieved. Kaido’s bounty as it stands is around 4.6B which is just over 300% of Luffy’s current bounty.
I want to tie this discussion back to the section regarding Alabasta just to remind you that similar to Kaido’s bounty dwarfing Luffy’s, so too did Crocodile’s bounty (being 270% of what Luffy’s was before the arc). Alabasta was also the place where Luffy received his highest percentage leap in Bounties, more than tripling his 30M to reach 100M. I think that just as Luffy defeating his first Warlord lead to his largest bounty increase Pre TS, Luffy defeating his first Yonko will result in the largest jump in Luffy’s bounty Post TS.
Putting this into perspective in regard to the influence and impact that this will have on the One Piece World, if taking out 1 of the 7 Warlords was enough to more than triple Luffy’s bounty, taking out 1 of the 4 Yonko is a much more impactful feat and thusly would entail a significant bounty hike. Not to mention that Big Mom is also in Wano and even if Luffy did not defeat her outright (meaning if Big Mom were not to fall in Wano), if Luffy frees the land of Wano at the end of the arc then he did so by fighting against 2 of the 4 Yonko and the only active remnants of the Rocks Pirates.
While the defeat of both Yonkos is forshadowed by Garp in 907 where he states “If they [the Rocks Pirates via Big Mom and Kaido] return they’ll be a threat… but events will find a way to surpass our imagination anyway.” and by the CP0 agents in their attempt to reassure one another that it is impossible for both Yonko to fall, it would seem odd for Big Mom’s character arc to have it end with her being fully defeated in Wano. Regardless freeing Wano would mean defeating the Alliance between the Beasts Pirates and Big Mom Pirates. Another point that those who are hesitant to place Luffy’s bounty above Kaido and Big Mom’s revolves around Luffy needing help to defeat Kaido. While not necessarily the same as the Grand Fleet in Dressrosa or Gang Bege in Whole Cake Island, Oda has set a reasonable precedent that Luffy’s allies receive significantly lower bounty increases than he does (Law played a huge role in Dressrosa and his bounty increase was still 40% lower than Luffy’s). This means that even acknowledging the help that Luffy had in taking down Kaido, narratively Luffy’s bounty will still be far and away much higher than those who fought with him on Onigashima.
This is not to say that his allies will not see a tremendous increase in their own bounty but Luffy is again acknowledged as the ring leader by both Kaido and CP0. Putting the idea of bounties back into the narrative of One Piece, it is often explained that the size of the bounty is proportional to the threat that one poses to the World Government. With the history of the Kozuki and Wano, the threat Kaido poses himself, and the impact that a functional alliance between Big Mom Pirates and Beasts Pirates would have on the scale of the world, it is pretty apparent that should Luffy be able to defeat Kaido and retake Wano he would pose the largest pirate threat to the World Government in the world.
I compiled all of this to say that I expect Luffy’s bounty after Wano to reach around 5 billion. Now this number is particular for 2 reasons, firstly because it would be the closest Luffy has ever gotten to his enemy’s bounty as ~5B would give him about 108% of Kaido’s bounty but keep him below Whitebeard and Roger of course. I think it is also important to point out that when Luffy started his Journey in the New World his bounty was 500M and a bounty of 5B would be a nice clean 10 times higher. In Enies Lobby, Luffy’s bounty jumped 300% for challenging the World Government, defeating Lucci, and saving Robin. In Whole Cake Island Luffy’s bounty increased 300% for challenging Big Mom, defeating Katakuri, and saving Sanji. Alabasta was the first arc where Luffy defeated a Warlord and his bounty increased by 333%. If we take Luffy’s current bounty (1.5B) and increase it 333% for the first time he defeats a Yonko that puts us comfortably at 4.99997B which is on par with my estimate for the post Wano landscape.
To preemptively answer some criticisms I expect to be levied against my position here I want to make the claim that if defeating Katakuri triples Luffy’s bounty, then it would make no sense what so ever to defeat Kaido and expect Luffy’s bounty to double to 3B or less. When we have examples of Luffy overcoming someone with a bounty astronomically higher than his, such as Crocodile who has the furthest gap between him and Luffy’s bounty of the entire series until Big Mom and Kaido, we see Luffy surpass him by both destroying their dream and passing them on the threat indicator level from the perspective of the World Government. Looking at the whole of Post TS One Piece from a narrative perspective, all of the adventures the Straw Hats have embarked on since Fishman Island have all been leading to the culmination in Wano. This arc itself is over 100 issues and we have been building towards this since Punk Hazard which began in the 600’s if I’m not mistaken. For over 400 issues we have been leading to the freedom of Wano and the downfall of Kaido and the payoff for this victory will likely be enormous – and rightly so. Even if Luffy has help defeating Kaido, freeing Wano from under the nose of two Yonko is reason enough to estimate that Luffy’s bounty will once again triple.
*Theory by bigd1gger