So far leading theory that I have seen is that Chopper will find a cure for SMILEs. I haven’t seen Vegapunk mentioned yet. So I came up with few point in favor of him.
1-Vegapunk will appear in Wano. In an earlier chapter, Orochi asked CP0 to bring him Vegapunk in exchange for continuing sale of weapons. So this plot point will be addressed by Oda later in Wano.
Also during Reverie arc, it was mentioned that Marines might come to Wano too with an Admiral. So Marines could use this to gain entry to Wano. They can send Vegapunk to Wano with an Admiral as an entourage/security detail while main invasion force comes in later secretly or They can send Vegapunk with CP0 on “temporary basis” and then send in an Admiral/invasion force using rescuing Vegapunk as excuse when Orochi, predictably, tries to keep Vegapunk.
2-Vegapunk is original creator of Artificial Devil Fruits. Ceaser tried to replicate his formula with Smile. So he is definitely best person to understand and cure smile side effects.
3-Last we heard, Smoker was on his way to Vegapunk with kids for Punk Hazard. Its possible that by this time Vegapunk has had time to examine these kids and info about smiles. Since Ceaser were experimenting on them during same time as developing SMILEs, he could have used some common ingredients, giving Vegapunk more of an understanding of Ceasar’s formula and motivation to stop SMILEs as it is putting his invention to evil uses (from marine/common people’s point of view.)
Some benefits for Oda for using this would be:
1-Chopper can meet Vegapunk and learn from him. So can Franky.
2-It ties in with CP0 and Orochi subplot.
3-It gives Marines a natural reason to invade Wano. Rescuing the beloved Vegapunk from evil pirates is a good excuse to start a potential war in Wano.
4-Vegapunk was rumored to meet Straw Hat Pirates at some point and explain Devil Fruits. Now, Vegapunk has opportunity to explain that at the end of Wano after the main fight. This way Oda won’t have to create an entire arc just for Vegapunk and we can move on to more crucial arcs like Elbaf and Raftel/LaughTale.
*Theory by fractalpanda
