"Earlier, I saw nobility and resolve that was hardened like a diamond, shining in your eyes. But you've fallen. Now you're just a piece of shit."
—Bruno Bucciarati to Pesci, JoJo's Bizarre Adventure: Golden Wind
Moral Event Horizon in this series.
- Phantom Blood:
- Dario Brando crossed the line before the series even began, with the reveal that he had worked his wife to death just to have enough money to buy booze. There's a reason Dio's murder of him is considered his one justifiable action.
- While Dio Brando makes it clear from his introduction that he is a horrible, horrible person, he crosses the line when he burns Jonathan's dog Danny to death out of spite after Jonathan beat him in a fight.
- Tarkus crosses the line when he crushes Bruford's remains while mocking him for his weakness. Though in Jonathan's eyes, him killing Zeppeli is this, as it's the exact moment Jonathan declares that all bets are off.
- Battle Tendency:
- Straizo crosses the line by betraying Speedwagon and leaving him to die in order to turn himself into a vampire.
- In Joseph's eyes, Kars crosses the line when he uses a body double during his fight against Lisa Lisa after having previously agreed to a fair fight, as it goes against the wishes of Kars' deceased friends, Esidisi and Wamuu.
- Stardust Crusaders:
- While animals usually have the excuse of not having a sense of morality, animals with Stands are granted enough intelligence to have one, so it's safe to say that Forever crosses the line when he spies on and tries to sexually assault Anne, an underage girl, while she's in the shower.
- J. Geil crossed the line before the Part even began by raping and murdering Polnareff's sister, Sherry.
- In the eyes of the Crusaders, Steely Dan crosses the line when he brutally murders Enya on DIO's orders. It doesn't help that, unlike most of DIO's minions, who do what they do out of an Undying Loyalty for him, Dan does it because he was paid to.
- Similar to Forever, Pet Shop is granted enough intelligence by his Stand to have a sense of morality, so he quite clearly crosses the line by murdering two innocent dogs and then attempting to murder their owner, a child, as well.
- Telence T. D'Arby is another one who crosses it before the events of the Part, when he imprisons the souls of countless victims inside dolls that he keeps as still-living trophies. Making it even worse is how he not only plays dress-up with them (including the female dolls) and is shown suggestively fondling Kakyoin's doll, but also in how he enjoys seeing their minds break over time.
- If Vanilla Ice didn't cross the line by killing Avdol, he definitely did by brutally kicking Iggy to death as retribution for Iggy forcing him to destroy a sand statue of DIO.
- If for some reason you didn't feel DIO crossed the line back in Phantom Blood, you probably feel he did when he forces Senator Phillips to drive over a sidewalk full of people. And if you somehow don't feel he's crossed the line yet, him killing Kakyoin was probably the last straw.
- Diamond is Unbreakable:
- While Angelo definitely crossed the line before the Part even began by raping two boys and murdering another, him killing Ryohei and attempting to kill Tomoko is seen as the moment where he proves himself completely irredeemable. Notably, he's one of the few enemies Josuke doesn't befriend after defeating, and after what he's done, Josuke giving him a Fate Worse than Death is agreed to be well deserved.
- In Okuyasu's eyes, Akira Otoishi crosses the line when he murders Keicho and steals the Stand Arrow, just as Okuyasu and Keicho were about to patch things up.
- Yoshikage Kira crossed the line before the Part even began by murdering Reimi when she was only 16-years old, with the implication that he would have murdered 4-year old Rohan had Reimi not saved him. And of course, this was just his first of many, many murders.
- In Josuke's eyes, Terunosuke Miyamoto crosses the line when he kidnaps Tomoko and Koichi.
- Golden Wind:
- Prosciutto crosses the line when he activates The Grateful Dead on a train to flush out Team Bucciarati, despite knowing that doing so will cause a number of civilian casualties.
- In Bruno's eyes, Pesci crosses the line when he tries to murder the rest of Team Bucciarati out of spite, as it's the moment Bruno loses any and all sympathy and respect for him.
- Melone crosses the line when he uses a random woman as a host for Baby Face's Junior, then has her disposed of once she's no longer needed. Not helping things is the implication that he's done this many times before, and had Giorno not taken him down, he would have done it again.
- Diavolo seemingly crosses the line when he attempts to kill Trish, his own daughter. However, he actually crossed the line before the Part even began by burying his mother alive under his house and then burning down his home village when someone finds her.
- Cioccolata crossed the line before the Part even began by physically and mentally torturing people in elderly care, and then recording them as they commit suicide. Note that from this point onwards, he only gets worse.
- Assuming it was Doppio's actions and not Diavolo's at the time, then the former definitely crossed it when he murdered Abbacchio.
- Stone Ocean:
- Pucci crossed this before the part began when he killed Emporio's mother with Whitesnake's illusory acid in order to gain her Stand disc.
- Sports Maxx crossed it when he killed Ermes' sister after she saw him carrying out a mob hit.
- Kenzō crossed it back when he was still a cult leader, manipulating over 30 people into burning themselves alive.
- Miumiu crosses it when she surrounds Jolyne and Emporio with the prison's entire security squadron and orders them to open fire on Jolyne, bragging about it to her face and not caring whether or not Emporio gets caught in the crossfire.
- Like Cioccolatta before him, Ungalo instigates a full-scale terrorist attack in an attempt to kill a small group of people who were hindering his boss's plans, not caring about the innocents killed as collateral. Unlike Cioccolatta, whose rampage was (mostly) limited to Rome, Ungalo's Stand spreads its chaos across the entire world.
- Donatello Versus may ellicit a bit of sympathy at first thanks to his Dark and Troubled Past, but that flies out the window when he uses his Stand to reenact a plane crash that had only two survivors, then places three sick children in the plane with Jolyne and Ermes, not only attempting to force them to choose between themselves and the kids, but also ensuring that even if they did sacrifice themselves, one child would still die. Versus also does not show any remorse for this, claiming that their deaths are Jolyne and Ermes' fault because they fought back against him.
- The nameless detective from Pucci and Weather's backstory might've crossed it before as being part of the KKK, but we see him definitely cross it when he instigates a riot and burns down the house of Weather's family, beats him up, and sexually assaults his girlfriend before deciding to hang him by the cliffside, causing Perla's suicide.
- Steel Ball Run:
- Funny Valentine crosses the line when he attempts to rape Lucy, only stopping when he realizes that she's become the vessel for the Holy Corpse.
- Alternate Universe Diego Brando crosses the line when he uses his female fans as Human Shields, and then blames Johnny when one of them gets killed.
- Dario crosses it when he attempts to murder his son, Diego by drowning him. Even the Dario from the original timeline never stooped that low.
- Benjamin Boom Boom fatally shooting his son Andre on purpose to get his magnetic blood on the heroes and showing zero empathy as he's literally dying.
- JoJolion:
- Tamaki Damo crossed the line before the Part even began by attempting to force Josefumi and Kira to choose which one will kill the other for their own life.
- Wu Tomoki crosses the line when he has Mitsuba unknowingly use her unborn child in an Equivalent Exchange experiment. This ends up somewhat subverted, however, when he reveals that he has no control over the results of the exchange, and that the possible death of Mitsuba's child was entirely out of his control.
- Jobin Higashikata doesn't cross the line when he kills Ojiro. After all, Ojiro came after him and his son, he was entirely in the right to take him out. However, he does cross the line when he murders Ojiro's girlfriend, Makorin, out of suspicion that she may be a threat to him (she wasn't). He also states that he would have murdered Makorin's daughter had she been a Stand User. If you don't feel he's crossed the line yet, you probably feel he did when he attempts to murder Yasuho, even after Mitsuba tells him that Yasuho helped save her life.
- Tooru might have already done it at various points, though most of it was due to the effects of Calamity influenced by his stand Wonder of U rather than him doing the deed directly. But he definitely crossed it when he attempts to perform the Equivalent Exchange on Yasuho to heal his own mangled body at the cost of hers.
- JoJo's Bizarre Adventure: Over Heaven: While DIO could tolerate Dario's abusive behavior to some degree, DIO notes that it was his selling of DIO's mother's dress that cemented his desire to kill him.
