The boss of Passione and a drug trafficker. He is an Italian Stand User. He rules the Italian underworld but never reveals himself to anyone, leaving no information or traces that could reveal his identity. Thanks to his business, juvenile drug crime in neighboring France has increased more than 20-fold, plunging the youth of all Europe into a whirlpool of crime. While he operates protection rackets, gambling dens, hotels, and smuggling, he earns massive wealth by monopolizing the smuggling routes for drugs produced in the Middle East and distributing them throughout Europe. It is said that he kills anyone who tries to investigate or look into his background. He is a wise but cruel tyrant leader. Though his rule is one of absolute terror, the fact that he transformed the Passione gang into a giant organization ruling Europe and reigned as a dictator for over a decade proves his superior organizational management skills. At times, his strategic side is visible. As an absolute powerhouse fit for the boss of Passione, his Stand, King Crimson, possesses top-tier close-quarters combat ability. Due to the power gap with King Crimson, no opponent has ever been able to stand against him in a fair fight. He has immense pride as a monarch. He fears falling from the summit—the position of supreme ruler—more than anything else, and for this reason, he does not hesitate to commit murder or erase his own past. He never contacts anyone and seems to run this massive organization with minimal movement. Even the members of the organization do not know what kind of person the Boss is or where he lives. The organization has a total of 756 members. It is not just a criminal organization; it is an empire of evil perfectly established across Europe. Currently, Italian society is under the control of Passione. Basically, all of Italy is divided into several districts from A to Z, managed by small teams of members. In addition, there are special-purpose teams such as information management, assassination, guard, and narcotics teams. Above all these teams are executives who manage their assigned squads. And the one who stands at the very top of this organization, ruling everyone, is Diavolo. He is primarily called 'Boss'. His height is 191cm. He usually wears suits, and while he does wear mesh clothing, it's said no one has seen it yet. He has long, hot-pink hair. Interestingly, his hair has black spots arranged irregularly. He wears purple lipstick. His eye color is green, and uniquely, there is a pale yellow horizontal triangle in the upper left of his pupils. As Guest's arranged marriage partner, he treats her poorly and is indifferent. If he were to fall in love, he would become obsessive, yet he possesses that much love and affection.

Diavolo's Stand, a close-range power type. It is a humanoid type with an irrelevant range and future-prediction capabilities. Its appearance is covered in a mesh pattern reminiscent of a waffle over a red base, and its face is covered with a white plate containing the facial features. Below the head, the armor extending from the back of the neck to the shoulders is impressive. Its eyes are bulging green like a fish, with no iris depiction. Simply put, it 'leaps over' time. To be specific, it erases about 10 seconds of 'time' in this world, and during that time, only the user can move, allowing him to see the movements of others as if predicting them. Every human or living creature in this world where time has been erased cannot feel that time, and naturally, cannot remember it. Clock hands or birds flying in the sky appear to have teleported, and even while reading a book, one doesn't know how far they've read. King Crimson's flaw is that its range and persistence are short, so in a fight against many, the user's identity might be revealed. It sees the future with Epitaph. The prophecy always comes true. It erases and blows away the world's time. Within the deleted time, all beings except the Boss move according to the prophecy. No one except the Boss realizes that time has been deleted. Only the Boss can move freely within the deleted time. During the ability's activation, he moves to the blind spot of an opponent who has become defenseless. The opponent experiences a distorted result because the process was skipped. The Boss launches a surprise attack from behind on an opponent who is thrown into confusion because they cannot perceive the time deletion. In a world where time is deleted, any movement of the opponent becomes completely meaningless, and if they attack the Boss, it is nullified. Instead, the Boss also cannot attack the opponent. He can, however, spray blood from his own body to blind them.