This is going to be a long post but I do believe that if you read through my points, I can convince a good number of you that Luffy’s bounty after Wano will likely surpass both Big Mom and Kaido’s.
To really break this down and evaluate how bounties in One Piece are really structured, I want to do three things 1) I want to look at Numerical values of Luffy’s bounty and the enemies he has defeated throughout different arcs 2) I want to look at the percentage differences between each of Luffy’s bounties themselves and 3) I want to discuss how the narrative of the One Piece manga also sets the tone for the bounty that we see Luffy receive at the end of each arc.
Lets start with the East Blue Saga: In the East Blue Luffy defeats 4 pretty notable enemies: Buggy (Bounty of 15M), Kuro (16M), Don Krieg (17M), and Arlong (20M). After defeating all of these opponents Luffy is awarded one of the highest starting bounties in the East Blue ever, a total of 30 Million.
I would first like to point out that this doubles Buggy’s bounty and is 150% of Arlong’s which sets a precedent for how Luffy’s bounties will overtake that of his opponents by leaps and bounds. To discuss the narrative element here, I want to propose that Oda intentionally made Luffy’s bounty so much higher than his adversaries here because it is a clear and distinct way to set Luffy above the rest of the rabble of the East Blue. What better way to indicate a character as special than to label him as far and away a larger threat to the World Government than all of the other pirates in the East Blue Saga. While this is an important foundation for both Luffy and the Straw Hats, what really gives insight into how Luffy’s bounty might look after Wano is the Alabasta arc.
Looking at the Alabasta arc there are some striking similarities that can be drawn between the arc in question and Wano. I know I said I would do some narrative analysis last but I want to start by pointing out the clear parallels that exist between Wano and Alabasta just to set the stage for my conclusion later. Both arcs take the Straw Hats to a number of islands which lead to their grand destination after agreeing to help an heir to the throne reclaim (or protect) their nation from the tyranny of one of the overarching “Big Bads”. In the Pre TS landscape these “Big Bads” are without a doubt the Warlords that serve as government sanctioned pirates and Post TS these “Big Bads” are the Yonko.
Crocodile and Kaido themselves have quite a few parallels as well. While Crocodile is not the first Warlord the Straw Hats have tangled with (see Mihawk), so too has Luffy tangled with another Yonko (Big Mom) before coming into contact with Kaido. Crocodile and Kaido also pose a unique challenge to Luffy in the first few fights because Luffy cannot seem to hurt the antagonist for some reason (Crocodile is a Logia and Kaido is seemingly nearly invulnerable).
Luffy then learns how to deal damage to the antagonist but still loses in the second bout setting the stage for Luffy to overcome his opponent in their next conflict (possibly).
Crocodile’s bounty prior to it freezing when he became a warlord was 81 Million which is about 270% of what Luffy’s bounty was coming into Alabasta. However, once Luffy defeats Crocodile we see Luffy’s bounty skyrocket 333% to total 100M which is roughly 125% higher than Crocodile’s established bounty.
Now these numbers are important for 2 reasons: firstly because this is the largest percentage increase we see in Luffy’s bounty from before and after an arc but secondly, this is also the first time we see luffy defeat someone with a bounty that is astronomically higher than his and as such, Luffy establishes himself as a threat to the World Government by taking out a Warlord. It is important to remember that the Marines and the Warlords were 2 of the 3 great powers keeping the world in check for the World Government and Luffy was beginning to tip the scales.