At the final battle between Giorno and Diavolo in episode 38. Diavolo got punched many times, and almost drowned in the river. He survived that and able to catch the edge of the sewer stairs, which...
This is poetic considering how many times Diavolo used his own Stand to manipulate reality. Also, it is a commonly held theory that evolving your Stand to Requiem gives you anything you want at that moment. Giorno wanted to kill Diavolo, and so he did, infinitely...
jojos bizarre adventure - How is Giorno able to do this to Diavolo ...
Diavolo's Soul, which is attached to King Crimson, was "set free" by Silver Chariot Requiem. Much like he shared a body with Doppio (without having full control), the same thing happened with Mista's body, now being inhabitted by the soul of Trish. Assuming Diavolo had no choice who he swapped with, this fact stands as mere coincidence. Doppio had no idea he was being inhabited by the boss ...
Where and how was Diavolo hiding where he was after the body swaps of ...
So, if Diavolo has to die infinitely following infinite scenarios, does it mean that in one of these scenarios, he obtains the arrow and pierces himself with it? My point is that in one of these infinite deaths, he gets King Crimson Requiem and shapes it to be like a direct GER counter or something and thus escapes his horrific punishment.
Even Diavolo alludes to how well connected his men have infiltrated different branches of Italian society. You have to remember a few things -- it seems that mostly every branch of Passione makes a fortune off whatever division they specialize in, all except for the Hitman Team, which only gets paid for kills.