He was always 2 people. There was only ever "just" Doppio when when Doppio went into Bruno's body, and Diavolo into Trish's
Luis Edwards
Additionally, Boss' body stayed in the Diavolo form (later inhabited by Bruno's soul) after the soul swap because that's the form he fell asleep in
Joseph Perez
>For me I thought Echoes Act 3's ability was going to be rhyming to make special effects happen I think it was supposed to be but Araraki never did anything with it but "Three Freeze".