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.
And of course, iron is also 
found within humans, as well.
ولا شكّ في أنّ الحديد موجودٌ 
داخل البشر أيضاً
Finalmente, también se encuentra
dentro de los humanos.
Finalmente, también se encuentra
dentro de los humanos.
Et bien entendu,
le corps humain en recèle.
E altrettanto ovviamente, il ferro è un elemento
che si ritrova anche anche gli esseri umani.
E é claro, ferro também
está presente nos humanos.
Стоит ли говорить, что железо есть 
и в теле человека?