Risotto figures out that Doppio must be a Stand user that the boss trusts in deeply because he’s able to hear the noise from a certain Stand. Risotto then uses his Stand Metallic against him. Metallic is able to control magnetic force and attacks Doppio. Doppio uses the part of the boss’s power he received from him. While they’re fighting, Risotto realizes that Doppio’s personality and actions seem to be changing and he realizes exactly who Doppio is.
It's an important substance 
that's within your bloodstream.
إنّها مادّة مهمّة موجودة في مجرى دمك
Ein wichtiger Stoff, der im Blut
durch deine Adern fließt.
Es una sustancia primordial
de tu flujo sanguíneo.
Es una sustancia primordial
de tu flujo sanguíneo.
Essentiel à un organisme,
il circule dans le sang.
È un componente fondamentale
nel flusso sanguigno.
É uma importante substância
da sua corrente sanguínea.