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 La Squadra Esecuzioni.
Diavolo is a veritably tall man in his 30s 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.
The biggest personality trait Diavolo shows is his obsession with erasing any trace of his history and keeping his identity 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. However, this is 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 other's 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. The most notable examples are Sorbet and Gelato, whom Diavolo had killed and in the case of Sorbet particularly, cut into pieces and framed in formalin, then delivered to La 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 directly confront 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 the newly-evolved Stand, 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 violently murdered a fortune teller that correctly divined his history. He has proven capable of restraint, as he told Doppio to spare a taxi driver after realizing that he hadn't seen the photo of Donatella that he was attempting to hide.
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. 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.
- Main article: King Crimson
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: Diavolo and Doppio are two souls that inhabit the same body. As a result, they can switch their personalities as well as their physical appearance. Compared to Diavolo, Doppio appears a lot younger and is described by a fortuneteller as looking too young to have children. Diavolo appears to be a lot taller, as well as more muscular. When he takes over, Doppio's freckles disappear, his voice deepens, and his hair is seemingly a different length. According to Diavolo, it takes a couple of seconds for him to completely take over Doppio's body.
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 on 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 altogether. 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 the 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 proof 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 trod 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.
- Diavolo to Doppio: Although in most cases it's self-preservation and survival (assuming killing Doppio would kill Diavolo, or vice versa), Diavolo seems to have a lot of affection for Doppio: he put Doppio in a very dangerous position of being the underboss instead of a usual subordinate, he often gave Doppio directions to being successful and even warned him to keep away from Nero and encouraged him to flee, and most peculiar of all, he has a habit of sometimes calling Doppio "[his] (cute) Doppio" with the more down-to-earth "watashi wa" pronoun. Noticeably, when Chariot Requiem activates and Doppio is shot multiple times by Mista, Diavolo almost immediately destroys and impales Narancia on a gate, instantly killing him, and begins to attempt more murders - before it happened, Diavolo was perfectly hidden away and everyone assumed Diavolo was in Bucciarati's body. On the other hand, Diavolo doesn't spend a single thought for Doppio whom he left for dead in Bucciarati's body.
- Doppio to Diavolo: While Doppio never learned the truth between themselves, he highly respects Diavolo and always called him "Boss" - though, whether or not Doppio knew Diavolo's name is unknown. Doppio also seems to be Diavolo's gofer, something he takes pride in considering how loyal he was to a point of stubbornness, and he seemed heed most of Diavolo's orders when he remembered them. According to Doppio himself before his death, Diavolo had told him that staying in Bucciarati's body would be dangerous and decided to move, leaving Doppio to his fate.
- Donatella Una: Although it's unknown how their relationship went, outside of Diavolo refusing to give her a name and never talking about himself, it can be inferred that it was largely positive. He took a picture of Donatella and she kept it throughout the years (although Diavolo becomes enraged upon learning that it still exists). Interestingly enough, Diavolo also never attempted on Donatella's life despite his ruthlessness. Likewise, Donatella loved Diavolo and told her daughter good things about him (albeit all lies Diavolo said before hand), and it's known that as Donatella died from her illness, she wished to see her lover again.
- Trish Una: It's inferred that Diavolo was never actually aware of Trish's existence until Donatella passed away and Squadra Esecuzioni began looking for clues on their former employer's identity. Diavolo realizes that their bond of blood allows him to sense her presence (the bonds of family being a reoccurring supernatural force in the world of JoJo). Immediately realizing that she could sense him as well and jeopardize his anonymity, he set in motion a plan to kill her with his own hands and used Bucciarati's group as pawns to bring her to him without letting the traitors capture her. In the final battle, Diavolo disowns Trish, wishing she never had been born. When she stops him from getting the Arrow during the final battle, he responds by having King Crimson punch clean through her stomach in a final attempt to kill her. However, she would survive due to Bucciarati's interception. Afterward, Diavolo would at the very least thank Trish for giving him the courage to attack Giorno Giovanna, as she revealed to her allies that Diavolo was attempting to run away, tempering his pride.
- Foster father: As a child born from prison, the priest took care of Diavolo for several years. He was openhearted with Diavolo's decisions of becoming a sailor and even decided to build a garage for him after seeing him and a woman on a date. However, this would also cause his death, as when he was digging into the concrete, he uncovered Diavolo's mother, which was of his adopted son's doing. On that same night, the Sardinian village was burned to the ground, with the priest among the casualties.
- Giorno Giovanna: Giorno planned to take down Diavolo since the beginning due to Passione's corruption of Naples, which included an agenda of drug trafficking affecting even children. Because of this, Diavolo retaliated and made Giorno a high-priority target. The two became bitter enemies over the course of Part 5, with Diavolo having invoked Giorno's anger during their confrontation after the death of Narancia, and Giorno helping to rouse Team Bucciarati's betrayal. During the race for the Arrow, Giorno alone figured out that Diavolo was residing in one of the group's bodies, causing the Boss to realize that Giorno was his greatest threat. With Bucciarati's demise, Diavolo confirms that Giorno was in fact the more dangerous individual due to his cunning, as well as the fact that he had planned to usurp him the moment the boy entered Passione.
- Bruno Bucciarati: Prior to meeting Giorno, Bucciarati was loyal to Diavolo, even though he was aware of the gang's involvement in the drug trafficking within Naples. Although Bucciarati initially had no power to take action, with urging from Giorno, he became determined to take the boss down as well. While this eventually led to Diavolo's killing him, Diavolo had declared his respect for Bucciarati, complimenting him on his prowess and valor.
- Narancia Ghirga: Although not directly interacting with Narancia, he was a threat nonetheless once he turned traitor. After Chariot Requiem was activated and Doppio was shot by Mista, Diavolo retaliates by killing Narancia, whom had a radar capable of finding anyone attempting to attack Chariot Requiem.
- Leone Abbacchio: Diavolo feared Abbacchio as he could easily find out whom Passione's Boss was with his powers. As such, Diavolo personally went back to Sardinia to intercept Abbacchio, and when given the opportunity, assassinated him while posing not only as Doppio, but also as a simple child playing soccer.
- Guido Mista: While Diavolo lacks a connection with Mista, Mista on the other hand shares his teammates' hatred and fear of the boss. Diavolo likewise regarded him as a threat just for betrayal. In the end, after the final battle with Diavolo, Mista was the last original member of Bucciarati's team before Giorno intact.
- Pannacotta Fugo: Fugo, even with all the evidence given to him, was torn between swearing loyalty to Bucciarati or staying on Diavolo's good side. Understanding the extreme danger of betraying Passione and Diavolo, Fugo ultimately chose to remain on Diavolo's side. In a rejected storyline, Fugo was also sent to kill his former friends, and if that was kept, Araki admits that Giorno would have needed to give the killing blow, which he felt would be too heartbreaking.
- Jean Pierre Polnareff: Polnareff is one of Diavolo's many enemies, though Diavolo did not have any interest in Polnareff particularly. As soon as Diavolo found out Polnareff had been investigating him, he made a personal and brutal attempt to dispose of him, but unknowingly left him alive. During their second confrontation, Diavolo did not care much that Polnareff was still alive, nor that he knew his name, but rather wanted to know immediately why Polnareff would possess an Arrow, displaying a sense of urgency on the matter of his familiar foe. Nonetheless, Diavolo would, without much effort, successfully put an end to Polnareff once more, stepping on his neck in order to check his pulse and confirm his death. However, Diavolo did not know that Chariot Requiem would save its former master by preserving his soul in the body of the turtle Coco Jumbo.
- La Squadra Esecuzioni: Diavolo not only refused to give La Squadra a territory and higher pay, but when the first signs of betrayal started showing, also killed two of their members, one of whom was sectioned into 36 individual pieces, which were then mailed individually back to the group. It should be noted that it took La Squadra two years to form a retaliation plan, which Diavolo immediately found out about and retaliated against. Diavolo disdained these assassins, but came to respect their leader, Risotto Nero to a degree, considering him a worthy opponent and granting him the dubious "honor" of a painless death if he obeyed his command of restoring his iron level during their fight.
- Cioccolata and Secco: As immoral as Diavolo was, he considered both of them complete monsters and only kept them in his organization as part of his personal guard squad due to their powerful combination and individual abilities alike. On their part, Cioccolata and Secco only obeyed Diavolo because he let them torture people and planned to overthrow him eventually.
Chapters / Episodes
- “Leave this place, Bruno Bucciarati... if you come out from behind that pillar... you will die.”
- “This is the end of the line. So, why shouldn't I tell you..? What you have witnessed and laid hands upon was your own future self! The "you" of a few seconds past saw your future self. That is the ability of my King Crimson! I eradicated time and forced it to skip!”
- “I shall not allow anyone, no matter who they may be, to threaten my everlasting climax. I will eradicate every last one of them.”
- “I can forecast the trails left by your movements... the trails of your future actions. Within King Crimson's ability, time is erased from the world and none can remember the footprints they left during this time! The clouds in the sky do not realize they have been scattered by the winds! An extinguished flame is not aware of the moment it has been snuffed! It is only the results! Only the results that remain in this world! All the actions you take in a world where time is erased are meaningless! And I alone can react to these actions! I can see exactly how you will act! That is the ability of my King Crimson!”
- “Even if you try to erase it, the past will always come back to lock true peace away from you.”
- “If anyone knows even the slightest fragment of my true nature!... They must not be allowed to live.”
- “Do you understand, Doppio!? I must crush my fear! Now is the time... I must overcome it right now! That is what it means to live!”
- “This is a trial... The trial of defeating my past... I accept it. In order to grow, we must defeat the mistakes of our past.”
- “The past... even when you break it to pieces and emtomb it in stone, it crawls out like a worm.”
- “Your grunts with your filthy abilities and your trifling intellects will neve be able to surpass King Crimson's forecasts... nor will you be able to circumvent them!”
- “I never predicted that anyone would be foolish enough to betray my gang, and I never imagined that anyone would discover my identity, ever. But, thanks to you, I have learned of this Arrow's true ability! This is a gift! A tribute that fate has given me for overcoming my past!”
- “You're all slimy mucus vomited into a toilet bowl! How dare you do this to me! (この便器に吐き出されたタンカスどもが！！このわたしに対して⋯⋯⋯！！Kono benki ni hakidasareta tan kasudomo ga!! Kono watashi nitaishite...!!)”
- “Who once said that "we all are soldiers chosen by fate"? But.... the world has shown me one truth.... Fate granted me the ability to erase time and precognize. There is no mistaking it... that is an obvious truth... The fate that governs this world selected my King Crimson to stand upon the invincible apex. I am no soldier.”
- “I am the Emperor. What I see is to remain upon the climax.”
- “I, Diavolo, am the Emperor! This fact remains unchanged!”
- “Giorno Giovanna! I will not even allow you the time to lament your death!”
- “My ability stands upon the apex of reality!”
- “You... little brat! (くぉのッ！！ガキイガァァァKono!! Gaki gaaaa)”
- “Stay away from me!!! (おれ の そば に ちかよる なああOre no soba ni chikayoru naaa)”
- Though never demonstrated, Diavolo can fluently speak Sardinian.
- According to a Top 10 List published in Weekly Shonen Jump in 2000, Diavolo is Araki's second favorite antagonist and fourth favorite character overall.
- Diavolo's voice actor in games developed by Bandai Namco Entertainment, Toshiyuki Morikawa, would later go on to also voice Yoshikage Kira/Sheer Heart Attack in the Part 4 TV Anime. Meanwhile, his TV anime voice actor, Katsuyuki Konishi, also voices Jonathan Joestar in the lost 2007 Phantom Blood movie.
- Diavolo's theme from the anime, aptly titled "diavolo", contains a small bit of the track "Alive" from the Jekyll and Hyde musical (around 2:21).