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.
That's strange. I could've 
sworn I was holding a phone...
هذا غريب. أكاد أقسم أنّني كنتُ أحمل هاتفاً
Seltsam. Ich hatte doch
ein Telefon in der Hand …
Qué raro. Juraría que tenía un teléfono…
Qué raro. Juraría que tenía un teléfono…
C’est bizarre,
je tenais le téléphone…
Che strano. Avrei giurato
di avere in mano un telefono...
Que estranho, eu podia jurar
que eu estava com um telefone na mão...
Странно… Я же держал телефон в руке…