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 made me spit out those 
razor blades and scissors!
!وتجعلني أبصق شفرات الحِلاقة والمقصّات
und mich Rasierklingen spucken lassen
und mir eine Schere in den Hals geschoben.
para que salieran
las cuchillas y las tijeras.
para que salieran
las cuchillas y las tijeras.
et tu attires les ciseaux
et autres lames que tu crées !
e mi hai fatto sputare
quelle lamette e quelle forbici!
e me faz cuspir as giletes e tesouras!
из железа в моём теле 
и вытягивал их наружу!