Ever since the Wano arc has started with the plot being overthrowing the Shogun of Wano Orochi and Kaido both with alliance rule Wano country. Where the expedition undertaken by Pirates, Mink tribe, Samurai’s and Ninja’s (there might be more addition to this group) everyone with different motives, originally Straw Hat and Heart Pirates want to defeat Kaido and Momonosuke and group want to free Wano from the clutches of Orochi and Kaido.
As the arc progresses it was/will be expected for Luffy to go up against Kaido and so did happened in the manga chapter 923 but unfortunately Luffy couldn’t even scratch Kaido, but only one hit from Kaido was enough to put Luffy out cold and get captured. Though this outcome was expected from the battle.
So if Luffy were to fight Kaido again how will Luffy power up?, I’ve read some fan theories of Luffy secretly getting trained from a legend or so, or coming up with a new gear5 as a power-up.
But recently released manga chapter have given us some clue’s of what or how Luffy will get his strength to next level or stronger. Remember Rayleigh who trained Luffy while in 2-year time-skip.
Now about Rayleigh everyone might be knowing about him but just to brief-up he was the right hand man of the King of the pirates Gol D. Roger. You can’t conquer the pirate world just on whim, they had to work their way up which signifies their strength as pirate crew. Coming to Rayleigh as quoted by Shakuyaku(Shakky) Rayleigh is 100 times stronger then all of the supernovas which is to be expected from the legend of a pirate.
Since Luffy was captured by Kaido and imprisoned in Udon-Prison it seemed Luffy was rather working out too much building his strength or rather training his Haki, while Luffy trying to save Old Man Kawamatsu fighting against the the prison guards, Queen announces execution of Luffy and old man through a Sumo match sending his underlink to fight but were piece of cake for Luffy, as stated in recent chapter Luffy showed remembering the lessons from Rayleigh, stating “The Haki he showed me at the beginning of my training… It was so advanced”, it was like wearing a suit of armor, Rayleigh was able to deflect elephants attack without even toughing it.
Now we know that Luffy is training based on his prior lessons from Rayleigh and observations and the experience has gained over the time. And the Power-up Luffy might gain is Advanced Haki .
Though Luffy is not able to properly utilize the ability and yet to master it to its full extend,
I’m not saying this will be the only thing Luffy gain as power-up there might me more as his not going up against just any random pirate but his facing one of the Emperor. And as for guidance you can’t just do strength training for 9 days and increase your power because there are only 9 days until final battle so receiving the training regimen like that from Rayleigh is out of the line.
Thanks for reading.