Soooo I have a theory or idea or whatever you want to call it regarding Luffy's final form. I have not seen this theory anywhere before so please let me know if someone else has had this idea. So I'll start by saying that I believe that Luffy will have 5 Gears. each gear having their strengths and weaknesses. While some like Gear 2nd and even 4th in my opinion are the not as much comedy based but meant to be more badass, whereas gear 3rd and gear 4th Full Mode are more meant to be funny. I believe that Gear 5th being the final form. Now in the world of One Piece there are so many OP characters and these characters did not get there over night. Except for Blackbeard kind of but even he had to bide his time sailing under Whitebeard. This being said, Luffy is still veery young and to say that he is going to be the top pirate in his current form at this age is kind of a slap in the face to all these other awesome characters that have been built up all this time. I think there may be another short time skip but nothing to age the Strawhats too much. Remember One Piece seem sto be aiming to have this kids make his dreams a reality. I know this sounds like a contradiction but bare with me. ***Warning*** Some Hunter x Hunter spoilers So all of that being said. In order to have Luffy become Pirate King and still be young enough to make this an even more extraordinary feat, I believe that Luffy will pull a Gon Freecs.... If you do not know who Gon is, he is the main character in the anime Hunter x Hunter. In this show is very young and new to using the powers of Nen. To overcome these gaps in skill and experience that he faces he uses Enhancing to generating extremely powerful attacks using his Nen. Now how this relates to Luffy. In Gon's fight with Pitou he is impossibly out matched in speed, Nen, and even power. Basically in every way and it is built up as Gon not really having a chance. He just had his raw rage towards Pitou. Now this is where it gets incredibly awesome! In at Gon's current age/size, his body is not capable of housing the kind of power it would take to defeat Pitou. So in a fit of pure rage/emotion, he enhances his entire body. He basically forces his body to age/grow to the point in which it is at its most powerful form which looked to be somewhere around his mid 20's. By doing this he was able to completely dominate Pitou. Luffy being a rubber boy is able to form his body into a variety of shapes and sizes. An example of this is him shrinking to a child form after using 3rd Gear against Rob Lucci. I believe that a Gear 5th Luffy will be capable of reshaping his entire body into the form at which he is capable of his maximum potential. Essentially making himself older. By doing this he, like Gon, would be able to access even more abilities than he currently does. I won't speculate as all that may be possible at this point, suffice to say there are a lot of new abilities and upgraded versions of current abilities that could be used. The issue with his current gears is that he is not able to use his Haki or Devil Fruit ability efficiently. This I believe is because of his current state. His 19 year old body is not capable of housing the power that he needs to generate to take on the level of opponents that he will have to for the title of Pirate King so he will force himself to the form/age that he will be able to access his maximum potential. I think this is a very possible outcome for the story because if you think about it. This will give Oda the ability to show what the future Pirate King Luffy will look as well as how he will fight, and still be able to bring him back to the youthful Luffy that we all know so well. Making him a very young but also extremely powerful Pirate King. So this is my theory on the future of Luffy in OP. If this theory exists already then please let me know because I am unaware. I would like to go over some different aspects of the theory with someone that can see this as a possibility. Thanks for reading this, more theories/discussions coming soon.