Diavolo/History

History
A lot of Diavolo's history is vague, but some facts are clear: born in an all-female prison during the summer of 1967, his mother claimed she had been pregnant for two years and there was no father, both within the jail and outside, that could've fathered her child. Because she still had years on her sentence, Diavolo was sent back to Sardinia to live with the priest in his mother's hometown. According to neighbors and friends, Diavolo was frank, yet timid and not too bright; he had also desired to be a sailor rather than a priest. Jean Pierre Polnareff claims he was very likely abused as a child due to forming a split personality but it hasn't been confirmed.

In 1984 to 1985 (roughly when Diavolo was 17~19), Diavolo met Donatella Una, who was vacationing in Sardinia when they met. Donatella fell in love with Diavolo, who was under the assumed name of "Solido Naso", and they interacted enough to sleep together and have Trish Una, whom Diavolo was never aware of. During this period of time, Diavolo told numerous lies about himself, all of which Donatella believed, and when they departed Diavolo made a promise to return and never carried through with it. In 1986, when Diavolo was 19, the priest (who by then had completely adopted Diavolo as his son) spotted Diavolo walking on the beach with a girlfriend (unknown as to whether it was Donatella or someone else). Believing it was time to get Diavolo a car, the priest begun to construct a garage, only to find a young woman, Diavolo's mother, buried alive in the dirt with her mouth sown shut. That night, a fire broke out and razed the village, killing the priest and five other people. Diavolo was listed as a casualty as well, but in reality had slipped off to Egypt to join an excavation. During this, he found six arrow heads by chance; he stole them, fled, and soon met Enya Gail, who told Diavolo of their use. He then sold five of the six to Enya for a large sum of money and very likely returned to Italy to create Passione. The arrow he took likely created King Crimson, Mr.President, and was given to Polpo and his Stand, Black Sabbath, to form the initiation test of Passione.

When he had formed Passione, he quickly sent his growing number of subordinates off to find and erase other Mafia families in Italy. During the entire time he ruled Passione, no one had ever met him in person or had seen his face. He also had Passione clean the streets of drugs and do various charity activities, which gave the outer impression of Passione doing justice. This allowed Diavolo to gather many wide-eyed idealists like Bruno Buccellati and have them join Passione.

In 1988, Polnareff and Jotaro Kujo set off to find the remaining Arrows that Diavolo had dug up. Polnareff had noticed that in Italy, crime and death rates had been rising to a point where they were 20 times higher than the average. As such, he set off to investigate Passione and Diavolo, eventually causing the two to meet face to face. In retaliation for nearly discovering him, Diavolo gouged Polnareff's eye, ripped off his arm, and shoved him off a cliff - breaking Polnareff's legs in the process - and declared him dead. However, Polnareff survived and found another Arrow; the one that could create Chariot Requiem.

In 1994, Risotto Nero joined Passione and Diavolo instated him as the leader of La Squadra di Esecuzione, giving him several operatives to run including Sorbet and Gelato. However, Diavolo never granted them territory, something all other units were given, and after five years the group sent a request for territory and a raise. When Diavolo rejected this offer, La Squadra retaliated by attempting to discover who their Boss was so they could extort these gifts. Unfortunately, Diavolo caught on and kidnapped Sorbet and Gelato, eventually torturing them and killing Sorbet while Gelato committed suicide. He then left Gelato's body at the assassins' shared apartment and delivered the 30 individual pieces of Sorbet, embalmed in frozen formaldehyde and framed, back to La Squadra's base. When La Squadra rebelled, Cannolo Murolo assisted them in turning against the Boss; regardless of whether Diavolo knew this fact or not, he dubbed La Squadra traitors.

At some point during the previous events, Vinegar Doppio "became a member of Passione"; i.e., Diavolo begun to use him to carry out missions in privacy without anyone seeing him in person. It's unknown when Doppio fully formed, "joined" Passione, and how many years he had been working under Diavolo - however, assuming Diavolo played his cards right, it was a long enough period of time for Doppio to become both fiercely loyal and completely believe that he was the Boss's most trusted subordinate.

In January of 2001, Donatella died due to an illness and Trish begun a quest to find her father. Due to his ties through Italy, Diavolo learned of this and sent Pericolo off to find her before La Squadra could.

2001 (Vento Aureo)
Because of his drug ring plan still reaching people, Giorno Giovanna became attracted to the events around Passione. Meeting with Bruno Buccellati, Giorno passed the initiation test, killed Polpo, and became a member of Buccellati's Gang. After the defeat of Mario Zucchero and Sale, Pericolo met with them, graduated Buccellati to Polpo's occupation, and gave them Trish Una as well as a mission to deliver her to Diavolo. This plan was done for a two-fold reason of killing off both La Squadra and Buccellati's gang and to personally kill Trish due to her sharing his genes, thus giving the world a clue to his identity. During this time, he traveled to various locations and dropped off objects to be used by Buccellati's gang; these include the key used to activate Mr. President in Pompeii, Coco Jumbo in a train station at Naples, and a disk located in Venice that would tell of his ultimate location. Buccellati's gang soon managed to collect all these, leading to Buccellati himself going with Trish to meet the Boss; however, by this point, Buccellati had teamed up with Giorno to kill the Boss, something Diavolo wasn't aware of. During the elevator ride up a tower where Diavolo said he was, he kidnapped Trish and slipped down the elevator shaft and into the basement. Buccellati followed suit and refused to leave, instigating a fight. Diavolo overpowers Bruno and delivers a fatal blow, but his would-be victim flees and is revived by Giorno. Due to King Crimson's issues with dealing with crowds, Diavolo allows them the chance to escape and brands the group traitors, promising a reward for anyone who kills them and his daughter.

Despite it, though, Diavolo orders his alter-ego Doppio to look into a particular matter: the house Donatella lived in in Sardinia still stands, and if Moody Blues was used at that spot, Leone Abbacchio would reveal Diavolo's face. Along the way, Doppio is questioned by a fortune teller who reveals that they're searching for their daughter - something Diavolo quickly takes care of - and nearly mugged by a taxi-driver. To make matters worse, Risotto arrives at the location of the house as well, planning on intercepting Giorno's gang to make one last grab at Trish. At first, Risotto simply assumes Doppio is a tourist, but upon seeing him react to the sounds of Aerosmith, the traitor realizes that Doppio is a Stand user and attacks.

The fight with Risotto is long and he nearly succeeds in killing Doppio many times, if not for Diavolo's interventions. He gives Doppio the use of Epitaph and throughout the fight encourages Doppio or orders him to flee. However the fight is largely in Risotto's favor, from the power of Metallica to Doppio's lack of experience fighting playing for the traitor. When Aerosmith intervenes, however, Diavolo takes control and gains the upper hand, using his abilities and Aerosmith's bullets to finish off Risotto. After replenishing his supply of iron by devouring nearby frogs, Diavolo attacks a child playing soccer and steals his uniform, giving him a chance to kill Leone while in disguise.

At some point after Buccellati's group leaves Sardinia to follow Polnareff's instructions, Diavolo gives Doppio back control and tells him to investigate the house. However, he knows they are moving towards Rome and he orders Doppio to get moving, as well as ask Cioccolata and Secco for assistance. However, when Doppio arrives in Rome, he's held hostage by Secco and is soon lending a hand in helping a once-again-dying Buccellati, bringing Diavolo to his old enemy Polnareff. Polnareff was taken by surprise at Diavolo revealing himself and attempted to get the Arrow away from him, but is soon caught and takes mortal damage from King Crimson. But before the final blow, Polnareff creates Chariot Requiem as a last resort, which caused everyone, Diavolo included, to pass out for at least six hours and switch bodies.

Upon reawakening, Buccellati's gang in their switched bodies figure out that Diavolo has switched places with Buccellati. Coming to the conclusion that Diavolo's soul would be in Buccellati's due to it being vice versa, Guido Mista, in Trish's body, fires several rounds into Buccellati's body. However, Diavolo's soul was piggybacking with Trish in Mista's body; he very likely comes to the conclusion that they're firing at Doppio and, enraged, breaks a nearby fence and impales Narancia Ghirga, in Giorno's body, on the fence and kills him instantly. With Giorno back to normal, the group realizes they were wrong and must retrieve the Arrow from Chariot Requiem, taking along with them Polnareff in Coco Jumbo's body. Diavolo takes his time and figures out how to stop the Requiem Stand before anyone else, but Giorno stops the group to try and figure out who is sharing a body with Diavolo. Diavolo panics and reveals himself by chopping off Giorno's arm, allowing the group to retaliate - however, he manages to defeat the Requiem Stand nevertheless, regaining control of his own body and sending Buccellati into heaven. Unfortunately, Giorno obtains the Arrow head and evolves his Stand into Gold Experience Requiem. When Diavolo attempts to skip time, Gold Experience Requiem traps him in an infinite death loop, starting with drowning in the nearby river, followed by being stabbed to death, being autopsied alive, and being hit by a car. The last of what is seen of Diavolo is him begging a child to get away from him.

Aftermath
In Purple Haze Feedback, it's briefly touched upon in the beginning that, within the six months between Diavolo's death and the story, Giorno had managed to successfully fool the entirety of Passione into believing he had been the Boss all along. Besides the drug team, lead by Volpe, it's unknown how many members of Passione actually bought this. Giorno had also obtained the assistance of the Speedwagon Foundation, giving Passione even more power than Diavolo had. Presumably, Diavolo was still in his looping death Hell during this time.