Gutsu Gutsu no Mi

Existing only beyond the main story, this Paramecia turns whoever eats it into a mobile furnace, capable of taking in ore and liquefying it deep within their frame. Two separate wielders have appeared across different media. Lambor Bukini carried the power during the 2013 stage production, and it resurfaced with Bill in the anime's Silver Mine chapters. English releases render the name as the Smelt-Smelt Fruit, and the eater earns the label of Blast Furnace Human.

After the ore has melted inside, whoever holds this ability can reshape and hurl that metal however a given situation calls for.

Ore gets swallowed, cooked to liquid within the eater, and then set again into any desired form, whether blades pulled from the belly or streams of molten metal launched at foes. A target can be locked inside hardened silver, and the wielder is free to sheathe their own frame in metallic plating while still moving normally, shrugging off the heat of their own metal along with most flame. As more ore goes in, size and might climb together, a scaling that Bartolomeo compared to a Logia. Building any weapon requires keeping a reserve of ore inside at all times, and each construct melts back down the instant it shatters. Swallowing too much causes the body to throw off heat fierce enough to melt everything around it, even enough to drop a whole island beneath the waves, and all the customary Devil Fruit drawbacks still bind the user.

On stage, Bukini warmed metal and raised steam without swallowing any ore first. Bill takes the opposite route, packing his internal furnace with ore until his frame burns orange, then forging blades and functional guns for his whole crew as much as for himself. Set up inside the Silver Mine with an endless stockpile at hand, he can eat in excess to swell his muscle and pour out rivers of liquefied metal, and when cornered he armors his entire body in layers of silver before flinging spheres of molten ore.