Luffy needs a massive power up to be able to upset Katakuri, he needs to evolve mid fight.
Now, this theory is about a possible new Gear 4th form of Luffy. This form will be achieved by combining Gear 2nd and Gear 4th. Although many had already speculated about this, i think i can still give you more ideas about what kind of form could Luffy achieves by combining these 2 gears. Also the potential it has to his fight against Katakuri. I’m calling this form the Flaming Bound Man.
Flaming Bound Man
As the name implies, this form will use the same concept as Luffy’s Red Hawk.
As you know, Red Hawk is a technique that Luffy uses which ignites fire while he is in Gear second. But how exactly does Luffy create fire? There are 3 things needed for this technique. Those are Gear 2nd, haki and friction. First Luffy will use gear 2nd to make his blood boil to produce heat. Then he will coat his arm with haki and stretch it to create friction hence creating more heat. These finally allows him to ignite fire.
With Gear 4th, Luffy already has the 2 things needed to ignite fire which is haki and friction. Gear 4th is already coated with armament and his muscles are already stretched which creating friction. So by combining Gear 2nd, his body will ignite fire.
But…. there’s a problem, the thing is Luffy also has a technique called Hawk Rifle which is very similar to Red Hawk. When Luffy is using it, he also uses Gear 2nd + Haki and strectch his arm but this attack doesn’t ignite fire.
So what is the difference between Red hawk and Hawk Rifle? I think it is the tension of Luffy’s muscle. I think in Red Hawk, Luffy tenses his muscles so much more than in Hawk Rifle.
By tensing his muscles more, it’s causing more internal muscle friction hence creating more heat. Basically it acts like a spark to Luffy’s Red Hawk. So i think it might be possible to ignite fire to his whole body.
After using Gear 4th and Gear 2nd, Luffy needs to tense the muscles in his whole body very hard. Kinda like Goku when he is about to go Super Saiyan mode.
Flaming Bound Man will give Luffy so much increase to both power and speed. Plus the flames can cause additional damage to the enemies.
Flaming Boundman is also perfect to counter Katakuri. Remember Katakuri has the ability to cover and trap his enemies using his mochi.
Even in Gear 4th, Luffy is still susceptible with this. It is possible for Katakuri to create a mochi huge and thick enough to completely trap and immobilize Luffy. This will be time where Luffy will thought about using fire to burn and destroy the mochi. This will be time where Luffy will use the Flaming Boundman.
Flaming Bound Man Forshadowing:
*Theory by jinz