Vento Aureo - Chapter 107 
Risotto loses a foot, but simply stitches it back with the aid of his parasite-like Metallica residing within him. He confirms Doppio's suspicions about his powers and how he can camouflage by covering himself with his Stand, but is ultimately unhinged.
Risotto materializes a bunch of knives and sends them toward Doppio, injuring him, and explains that because so much iron has been extracted from him, Doppio can't properly absorb oxygen in his blood and will eventually die from lack of oxygen.
Both fighters now see Bucciarati's group in La Costa Esmeralda, and aim to quickly finish each other. As Risotto disappears, Doppio foresees that he will apparently lose a huge chunk of his head.