Since the first fight between ‘Kaido’ and ‘Luffy’ everyone has realized that Luffy can defeat kaido. But the question everyone has in the mind is how and with what power Luffy can deal serious damage to kaido. Kaido not only has strong attacks but his body is instructable. Until now only a few people were able to damage him because of his strong scales. Recently in the manga, Zoro was able to give Kaido a cut that will be there on his chest forever. So what would be needed to defeat this monstrous power? Many speculations are going on from some time like ‘Gear 5’ or ‘Devil Fruit Awakening’ and there will be some big power-ups because it is an important arc that will shape the future of the One Piece world.
Gear 4- A new form
So during the Dressrosa arc when we knew Luffy can do nothing to defeat Doflamingo. There came a new form which none of us expected. ‘Gear 4’ when I heard it I was so amazed I was like “Hell yesssss’’. When while fighting Kaido, Luffy was able to hit him so many times but the problem was that those attacks were not effective on him because of Kaido’s tuff scales. While Luffy hit him so many times Kaido just used a single attack to knock Luffy and it was that easy for Kaido. But that does not mean Gear 4 is not effective against kaido. While on Whole cake island Luffy used a new form called Gear 4 – Tankman and then sent him flying. And again while fighting Katakuri, Luffy used Gear 4 – Snake man. With this upgrade he was fast and with improved observational haki, he defeated Katakuri.
So maybe there can be another form of Gear 4 which would be able to pierce Kaido’s tuff skin. Again with haki, it can be used to make it strong and defeat Kaido for good. But it will take more than it to defeat him because he doesn’t believe in fighting fair. He uses any means to win a fight. That’s how he was able to kill oden. That’s how he took over wano from Orochi.
Awakening

In the last few years, a new power of devil fruit eaters was introduced. This power is called ‘Devil Fruit Awakening’. In the last arcs of Dressrosa and Whole cake island, we saw the two strongest foes faced by Luffy awakening their devil fruit power. Until now we have seen Awakening of only Paramecia type fruit eaters. GUM GUM fruit is also a type of paramecia fruit. In awakening, a fruit eater is able to turn surrounding to match the same element as their devil fruit.
If Luffy awakens his devil fruit power he would be the strongest pirate there is no doubt about it but I think it would make more sense if he awakens fight with ‘Black Beard’. Because Black beard has now powers of Shirohige’s fruit i.e.‘Gura Gura NO mi’. With its power earthquakes can be caused easily. It is said to be a power that can destroy the whole world. Even the world government was afraid of it. So if Black beard uses it against Luffy and Luffy has awakened his devil fruit everything can be turned into rubber which might nullify Black beard.
Gear 5

Gear 5 is something which every One Piece wants apart from the treasure ‘One Piece’. Luffy can increase his speed with gear 2. And with gear 3 Luffy can increase his raw strength tons of times. Later, after the introduction of haki and a 2 year time skip Luffy was able to use gear 4 which was a combination of haki gear 3 and gear 2. Basically all his raw powers, speed, and armament haki. It gave a huge boost to Luffy and his bounty was increased to 1.5 billion berries.
Gear 5 can be introduced now which might combine his powers with his conqueror haki. Which can be a destructive force and change the current of war and future events. After the first fight, Kaido did say “We don’t need that many supreme kings”. Which indicates how powerful supreme haki is. And Luffy was practicing the flow of conqueror haki in Udon’s prison.
Advance haki – Ryou

When Luffy was prisoned by Kaido in Udon’s prison he was trying a method of using haki by flowing it but without touching the enemy and causing damage. he met a yakuza known as ‘Hyogoro of the Flower’. He found out that it is known as Ryou. It is another form of armament haki. He instantly became Hyogoro’s pupil and asked to train him. Although it was very difficult to control. Luffy did manage to pull some punches.
Also in the manga, while fighting Kaido at his castle he said he can defeat him with this and Kaido did dodge some of his attacks. So I think Luffy just needs to adjust more with his form of haki. It is possible to damage Kaido with this. It was shown in the manga. But I do think it is not the only thing that will be needed to defeat Kaido.
Defeating kaido would be a milestone in Luffy’s journey to be the Pirate King. Also, Luffy has to think something new because some punches would not be able to defeat Kaido. He might be able to break his scales but defeating him will be on another level. Oda himself has said that he doesn’t want Luffy to defeat kaido with just raw power and a punch. It has to make sense that’s why Luffy fought kaido and got defeated both times.
If you have some theories on this, please drop them down in the comment section, and let’s talk about our future King of the Pirates. Kaizoku Ou Ni Ore wa Naru!!