Diavolo/Introduction

"I must crush my fear! Now is the time... I must overcome it right now! That is what it means to live!"

- Diavolo, Chapter 552

Diavolo (ディアボロ) is the main antagonist of Vento Aureo.

He is mostly known as the "Boss" of the gang Passione, which corrupts Naples by dealing drugs in the streets, making him Giorno Giovanna and Bruno Bucciarati's superior and greatest enemy. Because of his obsessive secrecy, almost no one knows about his appearance, name and past. Diavolo is also the father of Trish Una, and commands Team Bucciarati to bring her to him whilst keeping her safe from the traitorous Squadra Esecuzioni.

Diavolo is secretly the alternate personality of Vinegar Doppio, and is a Stand User who wields the incredibly powerful King Crimson in battle.

Appearance
Diavolo is a veritably tall man in his 30's with a lean and semi-muscular build. In his first appearance, covered in shadow in all but his glaring eyes, he appears to have short, combed back straight hair and is wearing a suit and tie.

His appearance is drastically altered when fully revealed: Diavolo has long hair, leopard-patterned with various spots, parted in a zig-zagging manner; the bangs of which are propped and parted slightly to the side. The rest of his hair is cut straight across at his shoulders. In earlier depictions, varying amounts of Diavolo's hair were cut straight, inconsistently ranging from small locks to the entirety of his hair. His shirt, hidden under Doppio's sweater, appears to be made of complex mesh-wiring: it covers his shoulders and torso but down his back and abdomen are linked circles that are tucked under his belt, which in the back end in two~three long "coat tails". On his arms are elegantly designed floral sleeves leading down to a pair of wristbands. He also shares a pair of studded pants and seemingly sock-less loafers with Doppio. In most of his appearances, Diavolo has a slightly hunched posture when standing.

His eyes are unique as his irises are "fragmented", forming as spots and shards of whole irides with a triangular shaped highlight to them. However, while Bucciarati is in control of his body, they become normal with circular highlights.

His appearance differs greatly while operating as his alter-ego, Doppio. As Doppio is a completely separate soul sharing a body with Diavolo, they even have different muscular builds.

Personality
"In order to grow, we must defeat the mistakes of our past. The past... even when you break it to pieces and entomb it in stone, it crawls out like a worm."

- Diavolo The biggest personality trait Diavolo shows is his obsession with erasing any trace of his history and keeping his presence a secret from the world, a compulsion he tries to fulfill by any means. As he believes the mistakes of the past or simply the past itself is something to be defeated and destroyed in order for human beings to grow, he is exceptionally anxious about his past, linking it to fear, and being apprehensive of anyone learning of him. Even in the already secretive Passione hierarchy, Diavolo goes to excessive length to hide his identity and his face, issuing orders through several proxies or by computer so that nobody ever meets him personally. Diavolo lives most of his life in the shadows, hinted to perpetually travel across Italy hidden in Doppio, his alternate personality, and sleep in motel and hotel rooms exclusively. This compulsive trait of erasing his past is also an allegory to the inherent imperfection in King Crimson, specifically Epitaph's ability; While he can see into the future so as to avoid any mistakes, Diavolo's Stand ability cannot erase any low points or 'ebbs' in his life that have already occurred, forcing him to try to fix his errors through his own personal, manual efforts. Diavolo has a violent tendency to hunt and kill those who try to uncover any kind of personal information, or are merely susceptible to lead his enemies to him, as shown by his will to kill even his own family if it means keeping his identity safe - something highly vocalized through his attempts to murder his daughter, whom has never even met Diavolo herself and only knew things her mother passed down. This is however partially justified since family members within the JoJo's Bizarre Adventure universe share a mystic spiritual link, with Diavolo and Trish being able to sense each others' souls and know where the other is as well as if they are alive. Nevertheless, Diavolo is sufficiently pragmatic not to go on a killing spree every time he's about to be discovered, notably only using his power to confuse a hotel cleaning maid just for as long as he needs to erase any trace of his presence. As soon as he learns of a Passione member trying to investigate him, they will be dubbed as traitors and made examples of his wrath and absolute power. Most notable are, whom Diavolo had killed and in the case of Sorbet particularly, cut into pieces and framed in formalin, then delivered to Squadra Esecuzioni as a grim warning of the fate awaiting potential traitors. Diavolo is also persistent in keeping himself a secret even from Doppio, his most trusted subordinate and alter-ego. His second most prominent personality trait is his pride and confidence, firstly in his nigh-invincible Stand King Crimson, then in himself. Operating under a philosophy that King Crimson makes him invincible because it allows him to see the "pitfalls" in the future and avoid them, and allows him to manipulate Fate and reality by choosing to nullify arbitrarily chosen events, he justifiably boasts about King Crimson's power regularly. Diavolo notably claims that anyone's actions before King Crimson are vain, which is true to a degree. Secondly, Diavolo is intimately convinced of his innate superiority over humanity. Using epithets such as "Emperor" or "King of Kings", or like other main antagonists in the series, and using the prefix I or Me (この,  kono?) to announce his name in a sign of superiority over others. The mob boss doesn't doubt that he is fated to remain at the top, or 'apex' as he describes it, forever. This disproportionate pride is not only derived from his idea that people grow from defeating their past (and therefore, he has grown much due to his constant attempts at erasing any type of history of his), it is also backed by the firm belief that he's blessed by Fate; Diavolo's past involved extremely unusual circumstances such as an unnaturally long pregnancy in an all-female prison, making his birth nothing short of a miracle, then him finding six Arrows which would grant him his extraordinarily powerful Stand as well as his massive wealth. As an extension of the idea that he is blessed by Fate, Diavolo considers himself extremely lucky as well. He readily accepts any difficulty as a "test" he'll have to overcome to prove himself as standing above everyone, and though he can be subject to anxiousness or despair, his pride will prevail and he will constantly choose to confront directly whatever problem he has. This causes him to foolishly face Gold Experience Requiem head-on, although he did foresee Giorno Giovanna's death and had no idea of his new powers. Against Requiem Diavolo's confidence crumbled when it countered his time erasure and prediction abilities and left him powerless. When he found himself trapped in an endless death loop, unable to do anything about his situation, Diavolo panicked and his last appearance in the story has him frightened being approached by a little girl; His pride, confidence, and to varying degrees, sanity being completely crushed by his everlasting fatalities.

Other than his own philosophy of defeating the past so as to mature, Diavolo also lives by another thematic philosophy that results are the only things that matter in the world. As a decisive and assertive crime boss, Diavolo doesn't hesitate to take shortcuts or directly involve himself with troublesome matters if those actions are the quickest and easiest paths to an end. King Crimson's ability is an echo of this, and maybe the source of it, leaving nothing but the outcomes of situations, specifically those he himself sees fit to keep. He abuses his Stand's power as a means to produce the most favorable conclusions to his problems, and at the same time boldly prove his philosophy's claim to anyone that he confronts. Diavolo shows a degree of prioritization for these results and answers as well, notably when he, upon meeting with Polnareff whom he thought he killed years ago, only questions him as to why he would have an Arrow before attacking once more, rather than how he learned the name of the boss of Passione, or even how he managed to survive being thrown off a cliff into rocky waters. For Diavolo, keeping stability within Passione is secondary to maintaining power and his status as the boss; a mentality that eventually realizes the corruption of Naples, worsens the city's drug problem, and ultimately, leads to the rousal of Giorno Giovanna into joining the gang seeking to dethrone their boss. Diavolo only commands the obedience of his subordinates through greed or fear, causing the organization to even be corrupted within itself, members turning against each other, and multiple people to plot against him. Diavolo is also unforgiving of those he considers enemies, most especially traitors. Should anyone try to approach his alter ego Doppio and pry too much on his past, Diavolo violently rebukes them. For instance, he nearly gouged the eye out of the taxi driver that robbed Doppio and harassed him, and outright and violently murdered a fortune teller that correctly divined his history.

Diavolo has also demonstrated an inability to empathize or even understand other people's emotions and morals, especially those righteous, as well as an inability to properly interact with anyone, due in no small part to his overwhelming pride and antisocial secretiveness. When Bucciarati revolts, Diavolo openly theorizes that Bucciarati merely wanted to overthrow him or was opportunistic in his presence, without considering that hurting his own daughter deeply angered Bucciarati. Also forgetting that Squadra Esecuzioni would have a grudge against Diavolo after killing Sorbet and Gelato, he sent them to investigate Donatella's house, allowing them to uncover the existence of Trish. When interacting with others, Diavolo tends to act rather respectfully for his opponents and subordinates if they are obedient and competent. He compliments both Risotto and Bucciarati for their resourcefulness during their battles, and offers Risotto an honorable death. On a smaller scale, he compliments a fortune teller capable of accurately deriving his past as being "the best of the best" and gave a brutal yet painless death. However, Diavolo is also domineering and aggressive, taking his thoughts for absolute truths and ordering his interlocutor around; When he is angry, he is prone to shout insults and issue death threats. Diavolo approaches fights coldly, only considering confrontations as chores to be completed to maintain his supremacy. Diavolo favors eliminating his victims quickly using his King Crimson to confuse them and kill them in a single move. As seen with Bucciarati, Diavolo is shown slightly amused (or at least his Stand is) by the futile efforts of his opponents, and boasts regularly about his perceived invincibility. A pragmatic man, Diavolo still approaches the situation carefully, especially when Doppio is in command, and cannot use his full power. In an unadvantageous situation, Diavolo is patient, carefully undermining the enemy before using one critical attack, making him a most dangerous enemy during any battle, regardless of King Crimson's time erasure.

During his youth, the teenager named Diavolo was described as dim and timid, but well-meaning. He also expressed his wish to become a sailor and had a girlfriend Donatella, they were sufficiently close enough to have a child together. Due to the lack of further information and Diavolo's alternate personality disorder, it is unknown if this was a facade, or if he was genuinely like this before. Either way his secretiveness and ruthlessness were already present, having hidden his mother underground and having burnt his home village to the ground simply to hide his past.

For unknown reasons, Diavolo kept his mother alive, albeit trapped underground, and his old girlfriend Donatella alive, despite his willingness to kill his daughter.

Stand
Diavolo's Stand is King Crimson, an extremely powerful Stand with tremendous physical strength and the ability to erase time up to a 10 seconds time frame as well as predict anything that happens over the following 10 seconds. Although it has some limitations, King Crimson renders him essentially invincible in a fight as he can either foresee and counter the enemy's actions or render them meaningless by erasing the timeframe in which they happen.

Double Personality
Despite (likely) being human, Diavolo and Doppio share many minor abilities in changing their physical appearance. Doppio looks to be around 17 years of age and shorter than Bucciarati. However, while attacking that same man as Diavolo, he appeared to be a head taller, if not more, as well as being muscular. Furthermore, when Diavolo takes over, Doppio's freckles disappear and his voice deepens, and it may be possible that his hair can become longer or shorter than Doppio's. According to Diavolo, it takes him roughly 10 seconds to completely take over Doppio's body, but the transformation back to Doppio is instant.

While Doppio is in control, Diavolo has quite a few abilities, border-lining omniscience. He was able to tell that the taxi driver didn't see the picture of Donatella that Doppio was carrying, despite his subordinate's beliefs, and was later able to see the lurking Risotto. Diavolo also seems to be able to manipulate Doppio's memories, as Diavolo remembers everything and can see everything that happens to Doppio but not vice versa, although it's unknown how much of this is based off Doppio's possible poor memory. Diavolo can communicate with Doppio through any kind of object while not in control, granting his subordinate the belief that his alter ego is another person all together. Although we haven't heard the quality of these "calls" yet and whether or not the objects alter the quality of Diavolo's voice, Doppio can always hear his alter ego's voice through the object. Doppio also, on occasion, forgets that he's been able to communicate with Diavolo, but he consistently has never realized he's been using a broken or non-phone object. These "phones" have ranged from ice cream to frogs, to cigarettes to toys, and of course Doppio always carries on him a broken or dismantled phone headset.

Soul Manipulation
Diavolo is for unknown reasons, exceptionally knowledgeable about souls and their mechanisms, and is also equally skilled at manipulating his own soul.

Diavolo shows uncommon knowledge about souls, for instance being able to tell the near dying Bucciarati's state and then correctly guess that he can only see souls. Knowing that souls of family members have the same "scent", Diavolo is able to grant a shard of his soul to Doppio to disguise himself as Trish's soul. Moreover, under Chariot Requiem's influence, Diavolo has been able to control in which body he could go, although he otherwise couldn't freely control it.

Although Diavolo could exert subtle control of his own soul, he remains subject to the powers of soul-manipulating Stands such as Chariot Requiem.

Spiritual Connection
As Trish Una's father, Diavolo has a spiritual connection to her. By instinct, he can sense that she is indeed his daughter and was able to feel that she was alive despite being informed that the plane she was on had crashed.

Intelligence
Diavolo is a gifted tactician and is generally more intelligent than average.

As the proofs of Diavolo's abilities, the Boss has built a powerful gang with influence spreading across Italy in a matter of years. To avoid his enemies spying on him, Diavolo has proved to be imaginative in delivering his orders, using proxies, computers, dead drops, or even exploiting his subordinates' Stand abilities so only they could access the messages.

During a fight, Diavolo usually relies on his King Crimson's power and favors straightforward tactics like erasing time and positioning himself for a fatal strike. However, Diavolo has also shown to be rather observant, taking note of any event and keeping tabs on his enemies' abilities. He notably predicted that Giorno Giovanna's wit would become a real nuisance to his plans and treaded carefully with him. Diavolo also kept observing the apparently defeated Team Bucciarati from afar and managed to correctly analyze their state of mind and subsequently roughly guess their goals. Finally, Diavolo was the first and only one person to be observant enough to see the mechanisms of Chariot Requiem and guess its weak points, enabling him to disable the Stand effortlessly.

Diavolo has shown to be able of thinking on his feet, not panicking when he was chased by Bruno Bucciarati and Narancia Ghirga in a body deprived of hemoglobin and quickly using the surrounding fauna to replenish his blood. He also subsequently exploited this opportunity to assassinate Leone Abbacchio. Likewise in Rome, an accidental meeting with Bruno was exploited by him to approach Polnareff and assassinate him. Diavolo's arguably most effective tactic was during his confrontation against Risotto Nero, during which he exploited both the presence of Team Bucciarati, Risotto's own scalpels, and his own weakened state to manipulate Aerosmith into shooting only Risotto and turn the tables against the assassin.