During the Whole Cake Island arc Luffy managed to defeat two of the three Sweet Commanders (Cracker being the weakest and Katakuri the strongest) with bounties set at 860,000,000 and 1,057,000,000 Berries respectively.
In these two fights he developed two new forms for Gear Fourth: Tankman and Snakeman.
Additionally, after pushing his Observation Haki to its peak during his fight against Katakuri, Luffy gained the ability to see into the future to a limited extent. Going forward Luffy will want to be able to see the future like Katakuri can but train even harder so he use it at a greater level.
Right now I would place Luffy at the same level as the First Yonko Commander. Now what are the next steps for fighting the Admirals or a Yonko 1v1? So far we have three forms of Gear Fourth so will we see one more during Wano or even another Gear?
I don’t know how many more Gears Luffy could possibly go through. If I had to set a number I would say six (the last could happen in the Final War, a long time from now) but you don’t want to go overboard as it will start feeling silly so maybe it’s best if we stick to new forms of Gear Fourth for now. We also have yet to see his devil fruit Awakening powers. I’m imagining the most likely answer to that is making the environment rubber.
Despite saying all of this, Kaido doesn’t appear to be the sort of enemy Luffy can defeat 1v1 to me personally. Luffy may get the deciding blow but surely he will need help. In regards to the Yonko and pure 1v1 fights, I think he’ll have this against Blackbeard. Big Mom and Kaido will need teamwork. Your thoughts?
*Theory by ThisIsADraconianLaw