WARNING: The following contains spoilers for One Piece Chapter #1019, "Heliceratops," by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English via Manga Plus and Viz Media.
The revelation that Yamato is a Devil Fruit user in Chapter #1019 of the One Piece manga really doesn't come as a surprise, but the type of Fruit (some kind of Zoan) is rather interesting. It appears that Yamato can transform into what appears to be a fox or something similar. If it is a fox -- specifically a kitsune -- then that could hint at what Yamato's future in Wano could be.
In the Shinto religion of Japan, white kitsune represent the kami Inari. Something important to note about this particular deity is that they are depicted as male, female or androgynous. In mythology, Inari appeared in Japan riding a white kitsune carrying rice during a time of famine in the country. She is the kami of rice, fertility, foxes and a slew of other things. The most important aspect of her, in this case, is that she is a kami of prosperity and worldly success. Kitsune themselves are seen as supernatural creatures and can help a person gain wealth and power.
If Yamato's Devil Fruit power is turning into a white kitsune, then that could be a clear connection to the fox deity. Should he survive his battle with Kaido, the story could be setting up for him to become a shogun under Momonosuke. Though he's made it clear that he intends to join the Straw Hats once the battle is over, he could willingly take the title of shogun because it would be on his terms rather than under his father's direction. It could be that he stays on Onigashima to help re-establish order and help rebuild, aiding Momonosuke in guiding the country to prosperity, much like Inari, by acting as an advisor.
At the end of Chapter #1019 of One Piece, Yamato tells Kaido that if he didn't fight for Wano, then he couldn't call himself Oden. This could be another hint that he will decide to stay and help Wano recover after the battle is over. Even if he doesn't survive, his legacy would remind others that fighting for what is right, even in the face of adversity, is important. His story would be told alongside that of his idol, Oden. Only time will tell what Yamato's fate will be, whether it be following Luffy onto the sea or staying behind to be a guiding hand to the country of Wano -- either in life or death.
