Ahhh yes
Doppio and Diavolo
but this time the Diavolo is way more demonic than the current Diavolo.

Welp altering ego's in the wrong times is weird, and I suppose the other side of that kid would kill anyone anytime.... + that kid is the real owner of that body so....
Exorcism would surely help or else that ain't a normal guy, it's like a legion with Dissociative Identity disorder.