"Just when you thought you had reached the deepest depths of horror, it suddenly got worse. How to turn off that small voice inside your head that started to whisper that you should be glad — that now, if not before, your revenge was justifiable on any conceivable moral scale?"
Manfred Von Karma killed Edgeworth's father because he tarnished his perfect record, adopted Edgeworth, trained him to be a prosecutor, then set him up to be convicted of murder. He was the prosecutor who was trying to prove him guilty.
While we all knew Dahlia was a Bitch in Sheep's Clothing from the moment she popped up, her status as a monster isn't fully confirmed until the flashback case where she convinces Terry Fawles (implied to be mentally disabled) to kill himself because he doubted that she loved him. This is after framing him for murdering her and later her step-sister, and this is just as he's about to give testimony that might exonerate himself and convict her.
Matt Engarde crosses this long before he actually commits a murder, when he after essentially throwing away Celeste, who loved him, causes her new fiance, his rival Juan Corrida, to break up with her by revealing that she was once his girlfriend, leading her to be Driven to Suicide. Juan's role in said event could be considered his own Moral Event Horizon crossing as well.
The Hamlet special forces unit from Ace Combat X: Skies of Deception unleashes a biochemical agent on the innocent city of Santa Elva in order to kill civilians. It's a bit hard to feel sympathetic for the Leasath military after that.
It's very easy to hate Admiral Greyfield in Advance Wars: Days of Ruin, although the clincher is when Forsythe, the honorable general of the enemy Lazurian Army, surrenders to him and takes responsibility for all of the bad things his troops have done. Greyfield's reaction? He kills Forsythe and captures his army, threatening to execute them all. Soon afterward, when he finds out that Brenner is helping the Lazurians escape from captivity, Greyfield carpet bombs his position, killing Brenner and all of the surrounding soldiers in his area (including many of Greyfield's own New Rubinelle forces.
In Alice: Madness Returns, Dr. Bumby starts off simply as a Stalker with a Crush towards Lizzie, but he eventually gets worse. After he grows tired of Lizzie rejecting him, he sets her house on fire, killing her and her parents, and causing her sister to go insane. When Alice is healthy enough to finally leave the asylum, he then tries to hypnotize her, hoping to turn her into a prostitute like he had done with his previous patients.
in Assassin's Creed I, when it was revealed that Majd Addin not only didn't even believe in the Templar cause, he only joined them so he can get away with rape and murder.
Rodrigo Borgia in Assassin's Creed II crossed it even before the start of the game once players looked up into his profile about his past. If not, then there's him hanging Ezio's family, including his young brother.
Baldur's Gate: Irenicus would have been just unlikeable for torturing you in his lab. When he casually murders (and in at least one case, defiles the corpse ofnote no, not likethat; it's actually worse) two party members from the previous game and leaves you to walk through a dungeon complex full of people he's experimented on and left sealed in vats with only madness to keep them company, he becomes The Guy You Really Want To Kill.
Keep in mind this is after he'd already committed war crimes so horrible his own species, the usually Can't Argue with Elves, were horrified enough to exile him.
In Throne of Bhaal, Amellisan the Blackhearted crossed it when she guided thousands of Bhaalspawn to a "safe haven" so she'd have them all in one place when the time came for the mass sacrifice.
Wiseman from Baten Kaitos Origins crosses it in a big way when he kills everyone in Naos, an act so evil that Seph, perhaps the best example of a Blue Oni in the game up to this point, goes completely berserk. To the point where he makes a Deal with the Devil just so that he can personally kill Wiseman.
Shanath isn't any better in this regard. Even as someone who had been a major pain for the entire game, he manages to take it to a new level when he rips off Gena's wings. This pisses off Sagi to such a massive degree that when it is revealed later in the game that this wasn't Shanath's idea, but Quaestor Verus's, it's treated as that character crossing the Moral Event Horizon as well. Yes, the same event counts for two different people.
For those who have played Batman: Arkham City, all that needs to be said is "Protocol 10." For those who haven't, Hugo Strange's plan to eliminate crime in Gotham City is a mass execution of every living person in Arkham City. For the record, Arkham City contains a number of "political prisoners" whose only crime was knowing too much about his plans. When Batman makes him look at the results, his only response is "It's glorious, isn't it?"
And there's the Joker, who gleefully leaps across the Moral Event Horizon. He infects hundreds of hospitalized Gothamites with his poisoned blood just to blackmail Batman into making him a cure, and fatally shoots Talia al Ghul in the back to get it.
The game, meanwhile, will conclude that the player has crossed the line if you kill more than two Little Sisters. So, no, by the time Tennenbaum takes you in and says there may be hope for you yet, there isn't. Given that you're killing brainwashed little girls who can't help themselves, it's justified.
Nearly every major figure in Rapture can be said to have crossed the Moral Event Horizon. Steinman becoming the "Picasso" of cosmetic surgery* which, Cohen's definition of art, the whole Little Sister project.... However, while Tenenbaum does do actions that could count as crossing the line (collaborating with the Nazi prison camp, letting ADAM research go on despite being fully aware of the consequences, the whole Little Sister thing...) she still manages to appear sympathetic as she becomes The Atoner of the game.
However, truly special mention must be made to Dr. Sofia Lamb of the sequel. The opening cutscene is you bringing your Little Sister, Eleanor Lamb, around on a gathering expedition, and being attacked by a group of splicers as is normal. Then the good Doc Lamb shows up. After her minions cast Hypnotize on you, she forces you to shoot yourself in the head. While her daughter watches in increasing horror.
Stanley Poole is just as bad, in a horrible, fat toad sort of way. Not only does he turn Dionysis Park into a den of vice after being given control over the district, but he prevents Eleanor from reporting this by kidnapping her and giving her to the Little Sister program. Then, when Sofia escapes from prison, he decides to silence any remaining witnesses by sabotaging the district's pressure systems, drowning everyone left in the area. Is it any wonder that getting the game's best ending requires you to kill the asshole?
Speaking of hurting children, Comstock himself, in his audio diaries, revealed that at the Battle of Wounded Knee, he personally burned down Indian tents with children inside when someone accused him of having Indian blood. This time, however, it isn't his Moral Event Horizon. Comstock's Moral Event Horizon is ironically his baptism, or more specifically, using it to avoid taking any responsibility for his actions, leading him to become even worse than he already was. Compare it to our Booker, who is forced to face what he did, among other sins, as the story goes on and, while still not a saint, becomes a better man because of it.
Deliberately invoked to be Deconstructed. Booker, already not exactly the most psychologically stable of individuals due to his past, gave away his own daughter to settle his gambling debts. Normally, this would be a straight example. However, the moment the transaction was finalized, he suffered a catastrophic My God, What Have I Done? moment, went mad with grief and regret, chased down the people he sold her to, and tried to fight them to get her back. When that failed, he created a delusional fantasy about someone wanting Elizabeth and offering to settle his (now non-existent) gambling debts in exchange, all as a vehicle to justify his personal mission for atonement. By the end, his self-loathing is so great that he develops a genuine death wish, and he calmly lets his daughter drown him. This is quite a harsh depiction of the kind of psychological damage a person can do to themselves if they consider themselves to be past the Moral Event Horizon.
In BlazBlue, both Terumi Yuuki and Relius Clover are already a fine pair of jerks, but they surely crossed this line in the second game. At this point, it seems like they're competing in a "How far over the deep end can you go?" contest. At the moment, Terumi is winning this contest, if only for the fact that he's been around longer. However, what Relius lacks in quantity, he more than makes up for in sheer bastardry. Just ask poor, poorMakoto Nanaya…
Terumi created the BlackBeast that ravaged the world for years, joined the Six Heroes to defeat it when he realized it couldn't be controlled... then betrayed them and killed Nine, Kokonoe's mother, when she learned about his involvement in the Black Beast's creation. Adding on to this is how he did it — he manipulated fellow Six Heroes Trinity Glassfield into lifting Nine's geas on him, then killed them both and tossed them into a cauldron.
Relius transformed his own daughter Ada into a Nox, and left her half-finished with his son Carl, leaving them to fend for themselves. This is also knowing full-well that she's actively eating Carl's emotions and driving him into madness. He then used the experience to do the same to his wife, Ignis.
Also, Kokonoe's experiments on Lambda and her hand in the creation of Ignis are seen as crossing the Moral Event Horizon.
Though to be fair, she didn't know about Relius' plans to create Ignis until the plan was already underway and she couldn't do much to stop it with the NOL beating down her door.
Lord Yuna of Breath of Fire IV at first appears to be a simple officer of the Fou Empire's forces. He doesn't even appear to be as evil as some of the other members of the army (CoughRassoCough). Then, you learn near the end of the game that not only did he kidnap Elina (as opposed to all the times he told your group that she was no longer in the Empire), but he has forcibly genetically modified her body into that of a god, though one rendered immobile because her organs grew large enough to consume a building. The worst part? The entire point of this operation was so that he could use her as a source of ammo for the Carronade, a terrifying weapon that typically sacrifices the life of a person to fire a devastating Hex shot that leaves entire cities uninhabitable. The more physical and emotional pain the victim is put through before being sacrificed and the closer their connection to the target, the stronger the hex. His aim was to make Elina immortal so he could brutally torture her without her dying so he could fire the strongest shot possible at her kingdom. The game's ending hints that he goes on to create even MORE monstrosities like what he did to Elina.
The Big Bad of Call of Duty: Modern Warfare is obviously a psychotic terrorist, but crosses this line when he detonates a nuclear warhead in his own country.
In Call of Duty: Modern Warfare 2, General Shepherd's moral event horizon will undoubtedly go down as one of the most horrifying scenes in videogames, or any medium for that matter: A Big Damn Heroes moment turns into his Face-Heel Turn when Shepherd shoots the character you are playing as (Roach), shoots fan favorite Ghost in the face at point blank range for trying to respond, and has his black-coated troopers throw you and Ghost into a pit, pour kerosene all over your bodies while he watches, smoking a cigar, and then ignites the kerosene by throwing his lit cigar at it, burning you alive. Sure, in some ways his plan means well, but still. Thankfully, in the final battle, Soap tears out a knife stabbed into his chest — that Shepherd put there — and throws it right at the sorry guy's eye, killing him with an Eye Scream.
You, the player, cross the Moral Event Horizon during the famous level "No Russian." Masquerading as a Russian terrorist to infiltrate Makarov's gang, you and he march through an airport and slaughter hundreds of civilians with automatic weapons. General Shepherd tells you in the mission briefing "This will cost you a piece of yourself," and he is not joking. Even though you do have the option to not shoot the civilians (you can either not shoot at all or purposely shoot over their heads), it doesn't excuse the dozens of SWAT cops you gun down on your way out.
You can skip the level, though (even during the level itself), and the game reminds you of this several times leading up to the event itself.
Plus one in Black Ops, and how. During one of the Vietnam levels, you hear a recording cementing the bad guys as complete, irredeemable monsters, wherein one mentions the effectiveness of the evil phlebotinum Nova 6 on infants. And now I must scream.
Makarov crosses it by orchestrating and leading the "No Russian" bit above in MW2.
And he crosses about 5 more during the course of Modern Warfare 3. In no short order:
He kidnaps the Russian President, and plans to use his daughter to extort the Russian nuclear launch codes out of him, so he can turn all of Europe to glass.
He unleashes a lethal toxin into the streets of various cities around Europe, killing thousands of soldiers and citizens to pave the way for an en masse Russian invasion.
He sets a trap to kill the remnants of Task Force 141, which ends with Soap's death, and Price losing trust in Yuri for knowing Makarov.
As it turned out, HE was the one who gave the order for the aformentioned warhead's detonation in the original Modern Warfare.
He levels most of Berlin to get the Russian President's daughter, and when he has her, he TORTURES her to get the Russian president to break.
In essence, Makarov orchestrates WWIII just to further Russia's power and for profit. If there is anyone more capable of evil, I'd like to see it.
Command & Conquer Generals: the GLA's crowning moral event horizon is them using bioweapons on China's cities.
In Command & Conquer: Red Alert, the very first cutscene for the Soviets has Stalin and his cronies casually discussing the effects of Saren nerve gas on a village of alleged dissidents. Then, just to remind you that you're one of the bad guys as well, your first mission is to kill the villagers who escaped said gassing.
While in the second game, the Soviets are more quirky, they cross this line in the Allied campaign when General Vladimir nukes the city of Chicago, just as you won the city back.
The Conduit ends with Adams setting off the self-destruct sequence in his base after you infiltrate it. In the sequel, we find that the explosion has destroyed D.C. and has Adams joke about how your family was in the area. Whilst commenting on how radiation is an unpleasant way to die.Jerk.
In The Darkness video game, the death ofJenny serves as a Moral Event Horizon for both Paulie Francetti and The Darkness itself. Paulie for executing her and The Darkness for restraining you as you are Forced to Watch and sadistically joking about it all.
The Darkness: "Aww, what did they do to poor Jenny?"
That is, assuming Paulie hasn't crossed it already by blowing up the orphanage where Jackie grew up with a rocket launcher. With the kids inside it. Out of spite.
In Warhammer 40,000: Dawn of War II: Chaos Rising, each squad has a Corruption meter, which goes up with evil actions and down with good actions (or penance). When a squad reaches the maximum level of corruption, they become "Lost to the Dark Gods" and are irredeemably evil, regardless of actions including killing a greater daemon and saving sub-sector Aurelia again. Doing this results in a change of endings depending on how corrupt you became. The five endings are: 100% pure, become the Brother-Captain of the 4th Company; pure, become marked as a renegade by the chapter like Gabriel Angelos; Neutral, be banished to the Eye of Terror for 100 years, and on survival you may be allowed to return; Evil, be executed by Gabriel Angelos for heresy; 100% Evil, become a Chaos Lord for the Black Legion.
The Raskols — One of Banoia's violent gangs, the Raskols decide that a Zombie Apocalypse is the perfect time to start doing whatever the hell they want, randomly gunning down and stealing from the living and the dead with equal mercilessness. The worst have to be the Raskols who take over the police station, selfishly turn it into a fortress for themselves alone, shoot at any survivors who try and approach for aid, are eventually revealed to have zombies caged up and be kidnapping survivors to feed to them, and finally, when Jin tries to be a good Samaritan and share some supplies with them, they steal them all and rape her. The characters feel no guilt in slaughtering their way through their ranks and letting the zombies have the survivors, and most players won't either.
Koritoia Ope — A superstitious witch doctor who embodies the worst ideas of the misogynistic medicine man; he sold his own daughter to another man as a slave to pay off his gambling debts, he locked said daughter in a tomb to starve to death for running away from that fate to the city and daring to return after getting herself educated, and he tries to beat said daughter to death as an evil spirit when he is "persuaded" to take the player characters into the aforementioned tomb. Things get even worse when we find out that he is ultimately responsible for the zombie outbreak; the first roving infected, who went on to spread the plague across the island, were his tribesmen, who caught the disease because of his giving them zombie-infected brains to eat as part of a holy ritual. Part of the reason he sealed Yerema up to die is because the infected were not as they were supposed to be. Purna shooting him dead is richly deserved.
He's even worse in the novel of the game: when Yerema dared to return, he ordered some of the men to ritually torture and rape her for leaving. This is how the infection first reared its ugly head; the first zombies were her rapists.
Charon — An international hacker-for-hire who has willingly worked with every terrorist organisation on the planet, from Al-Qaeda to the Yakuza. He's deeply involved in the zombie outbreak and is intending to take a sample strain of the virus and make a fortune by selling it as a bio-weapon. He manipulates all of the playable characters, setting the immune quartet against Colonel Ryder in the process and convincing them to help him obtain a bio-engineered super-potent strain of the virus for him, murders a scientist when he's insistent on creating a cure for the disease as well, and is unrepentant of the nightmares he will unleash in pursuit of cash.
In Dead Rising, there is a rival photographer, who helps you learn to use the camera, and has photography contests with you, but in the last day, he ties up an innocent man, and was going to take a picture of the person "Crossing into zombiehood". By the way, if you don't get there at a specific time, you'll find out he is not kidding.
Thankfully, the game lets you, in your metagame precognition, kill him before this even begins to happen... while he's giving you the tutorial on how to use your camera. The game still counts this as a Psychopath kill.
Depending on the player's choices in Devil Survivor, different people can end up crossing the line. One major example is Keisuke Tagaki, who loses it after finding out that demons aren't the only threat in the lockdown and decides to deal with it by slaughtering anyone they judge irredeemable. Again, the player decides whether they've gone too far with their well-intentioned extremism, or if they want to pull them back from the brink.
Maghda was originally a quite Disney-ish witch who mainly sent cultists after you and tried to beat you to the three pieces of the Stranger's Sword. When she burns the town of Wortham to the ground and then tortures and kills fan favorite Deckard Cain, that's the moment when she stops being a sideline nuisance and becomes a full-on horrific villain — and she only gets worse from that point on.
Adria crosses this big-time with probably the cruelest betrayal of the entire saga at the end of Act III, by using Leah, her own daughter, as the vessel for her master Diablo to be reborn as the embodiment of all seven of the Great Evils in one being, the Prime Evil, by means of the Black Soulstone that she had tricked you into filling with all seven Evils for her.
The Grand Maester's proclamation during the Reaper of Souls sidequest, The Templar's Reckoning, is called "damning" by Kormac for very good reason. Basically, it announces the Maester's intent to conscript every citizen of Westmarch and beyond into the order, with his Inquisitors visiting the same horrendous torture and brainwashing that Kormac and Jondar went through upon every last one of them in order to make them Templars. It is this proclamation that convinces Kormac that the order is beyond saving, and that both the Grand Maester and the Inquisitors need to answer for what they've done.
From Disgaea 3: Absence of Justice, there's Super Hero Aurum. He wasn't a pleasant person to begin with, killing demons and Overlords just for who they are, his latest being the Gentle Giant in charge of the Evil Academy. He crosses the horizon, however, when he takes over as the butler for said Overlord's son and messes up his perception of the human world, all so he can have a new Overlord to add to his record. He crosses it further when, just to make sure Mao doesn't relapse, he sets an Obvious Trap for the princess Mao is escorting, to make certain her "hero" bodyguard (which also happens to be his number one fan) triggers it and dies, only to drive home that Humans Are Bastards and the good ones wind up dead. In short: he messes up one kid and gets another killed just for the prospect of remaining the Super Hero and to stroke his own ego. This quote sums up everything...
Raspberyl: What kind of nerves do you have?! It's beyond honor student level.
In Dogs Life, Miss Peaches is a supposedly nice business woman who is number 1 in cat food. But in the game, it is revealed that the new cat food brand she is releasing is made from dogs that she and her lackeys have kidnapped. And she has a huge machine that is unnecessarily long and unnecessarily brutal to kill them!
The dwarf Paragon Branka doesn't so much cross the horizon as she flies across it, laughing the whole way. We find out just how completely depraved and insane Branka is when it is revealed that in order to reach the Anvil of the Void, she sacrificed her house — three hundred plus dwarves — to the Darkspawn and allowed the women to be taken to become part of the Broodmother (a process that defines horror) just so she could have Darkspawn to throw at the traps surrounding the Anvil. The sole survivor, Hespith, explains it in simple terms:
Hespith: But the true abomination... is not that it occurred, but that it was allowed. Branka... my love... The Stone has punished me, dream friend. I am dying of something worse than death... Betrayal.
Arl Howe crosses it in the Noble Human origin story when he slaughters his best friend's entire household, including his best friend's young grandson and helpless daughter-in-law, out of nothing more than ambition.
Marjolaine crosses it in the DLC Leliana's Song where the player gets to see Marjolaine's betrayal of her friend/lover firsthand. When Leliana discovers Marjolaine has been committing treason against Orlais, she confronts her about it, not because she's angry at what Marjolaine's done, but because she fears for Marjolaine's safety. Marjolaine responds later on by knifing Leliana in the gut, hands her over to Captain Raleigh to be tortured, and strongly implied to be raped, and alters the document so that Orlais believes Leliana is the traitor.
Anders crosses the line when he blows up the Kirkwall Chantry, killing the Grand Cleric and many other innocent people in order to destroy any chance of compromise between the Circle and the Templars.
Then Meredith followed him when she used it as an excuse to annul a Circle of Magi that Anders never even belonged to. Just like he knew she would. The mages in the other circles considered this an In-Universe moral event horizon for the Templars and the Chantry. At least half of them rebelled on the spot, while the ones who didn't followed within the next year in response to the Templars' efforts to get the situation under control.
Then Orsino crosses it when he reveals that he knew about and protected the Serial Killer blood mage Quentin. While he downplays his crime in the Mage path, he is wholly unrepentant in the Templar path about being complicit in the deaths of several innocent women, including Hawke's mother Leandra. He even uses the fruits of Quentin's research to turn himself into a literal monster after the reveal.
Mother Petrice crosses it when she murders Seamus Dumas, tries to frame Hawke for it, and plans on using the entire affair to incite the citizens of Kirkwall to rise up and wage war against the Qunari. Her apathy towards Hawke pointing out how it will be a massacre on both sides of the conflict further solidifies just how much of a deranged zealot she really is.
Due to the game's Grey and Gray Morality, a lot of Hawke's actions have some sort of justification. However, there is absolutely no excuse for selling Fenris back to his master, especially since he had been your loyal comrade for 7 years. It's so awful that almost all of your companions — who almost never agree on anything — will call you out on it.
Mentioned in-universe, in Dungeon Maker II: The Hidden War, by the male main character in regards to Crimson. At first Crimson appears to be a Manipulative Bastard at worst, with a little bit of foreshadowing that he might actually be an outright villain. Then you get to the earth ruin. In the middle of talking to a demon ghost Crimson shows up, destroys the frightened ghost for no really good reason, then tries to convince the Dungeon Maker to murder Niko, an innocent little boy whose only "crime" is being half witch. The Dungeon Maker explicitly states this is the point where he went from simply distrusting Crimson to outright hating him.
In the first installment of the Eagle Eye MysteriesEdutainment Game, during Book 2's version of "Case of the Crazy Compass," the mystery's guilty party (Dave Grant) slips a powerful magnet into Alex Hane's backpack; this has the effect of severely messing up Alex's compass while he's out in the woods with the rest of his Explorer Trek club, causing him to get lost for hours and putting him at risk of experiencing the very real dangers associated with getting lost in the woods — and the perp put the magnet in the backpack knowing that Alex and his group would be going into the woods. It becomes even worse when you learn the motive for the act, as well (because Alex's science project had earlier beaten Dave's special project on magnetism), and it's especially telling that the character doesn't show up in any subsequent cases in the game's linear order.
In one of the background books in The Elder Scrolls III: Morrowind, an axe-fighter named Ellabeth becomes part of a love triangle. She kidnaps her rival and leaves her in a room with three doors, telling her that one door will lead to freedom, another to the guy, and the third to a demon that will kill her. That's a nasty enough revenge, right? As the woman tries the doors, it turns out there is no demon: one door is the way out, and behind the others are the two halves of her boyfriend. It's called "The Third Door."
This one's arguable. Not because Ellabeth was enacting revenge for being wronged, but because, before leaving the girl to her fate, she takes pity on the poor thing, points her to the correct door, and tells her to ignore the other two and just leave. Her advice is disregarded.
In the embellished historical account of Morrowind's war with the Empire, we get a plethora of bastards merrily hopping across the MEH. The Akaviri potentate and his son gleefully plot the absolute destruction of the Emperor and his minions, callously catching innocents in their web of intrigue, while they are at peace with the Empire. A deranged Khajiit lord sets Molag Bal, one of the most sinister and cruel Daedra Lords, on a helpless town because a bard from there had told him a depressing tale. Later on, to get revenge for Lord Vivec of Morrowind blacklisting him for incompetence, a mercenary manipulates a poor bereaved girl who had been trained in witchcraft into summoning Mehrunes Dagon to destroy the capital of Morrowind. The mad Empress has her own son assassinated, and the Emperor (after being tricked into believing that his concubine was an assassin), casually remarks to her that he's going to free her, but he thinks he'll have her innocent little sister brought in as her replacement.
Outside of the literature within Morrowind, Lady Almalexia, one of the three mortal gods of the Morrowind Tribunal, goes insane with power and uses her reincarnated lover (whom she betrayed to his death the first time) to carry out her increasingly unsettling orders, and finally sends him off to murder one of the other members of the Tribunal based on sketchy evidence. When the player arrives, they find Sotha Sil already dead, and Almalexia arrives to try to murder you before going on to take care of Vivec so that she will be the sole ruler of the Temple.
You in Evil Genius, naturally. Most of the Acts of Infamy you can perform are of the "darkly hilarious" variety (ordering your soldiers to club baby seals on live television), or they're deeds that aren't really evil but simply plain old Trolling (ordering your minions on an operation to deprive the British intelligence of their tea). Basically, the overwhelming majority of possible evil deeds run on Rule of Funny. Several of the actions you need to perform to defeat the Super-Agents are also like this: South American agent Mariana Mamba? Give her reverse-liposuction to make her hideously fat. North American agent DirkMasters? You dunk him into a vat of chemicals obtained by his steroid and sweat-riddled gym towel, turning him into a muscle-bound mutant. Chinese agent Jet Chan? Have him curbstomped in a rigged martial arts tournament so he flees and meditates on his defeat. See? All of these are presented as humorous and fitting, and most importantly, they are defeated in such a way that they are fine apart from their appearance or pride. Not so for the Russian agent, KatarinaFrostonova. How do you defeat her? You take the only thing she has ever cared about - her childhood teddy bear - and you tear the thing to pieces in front of her and mock her for it. She flees your base in mad hysteria and it's implied that her Heroic BSOD is so profound that she's forced to be retired from service. This is notably the only evil deed that the game presents as a You Bastard moment rather than something to laugh at.
In Fallout: New Vegas, the player can cross this. The Moral Event Horizon might be selling Arcade Gannon into slavery, leading to his suicide or crucifixion, letting Mortimer (a high class cannibal) use one of your human companions as the main course of a banquet, firing the Archimedes Kill Sat on the NCR at Helios One, blowing up the Brotherhood's bunker, or teaming up with the Powder Gangers to destroy Goodsprings and kill everyone in it, including the guy who saved your life. Or other things.
Failing "Don't Tread on the Bear", which occurs at some point in all of the non-NCR story branches, locks you out of any further NCR quests (including Boone and Cass's companion quests), and once this happens in the Legion story path, the NCR are permanently hostile on sight; they will also declare you a terrorist if you kill any of their leaders.
The Lonesome Road DLC allows you to nuke both the NCR and the Legion, with a quotation ofPlanet of the Apes's ending if you have the Wild Wasteland trait.
The effect of many of your evil actions is kinda ruined, as you can erase the negative consequences of many such actions by giving water to beggars or donating to the church.
Actually, the very act of turning the purifier on gives you the same amount of positive karma as poisoning it does negative. So, for killing the entire wasteland population, the karma system just remains somewhat indifferent to you. If you plant the virus and send a follower in to activate the purifier, however...
At the end of the "Broken Steel" DLC, you can choose to use the orbital nuclear strike to blow up the Citadel (base of the Brotherhood of Steel, one of the few good factions in the Capital Wasteland) instead of the Enclave's Mobile Crawler, which makes you truly irredeemably evil, this being the last story mission of the game. The only positive outcome is a Bragging Rights Reward in the form of Callahan's Magnum, found in a safe within the smoking ruin.
It should be noted that if you have high karma followers, they'll mostly just go along with you as long as you stay high karma. However, there are certain things you can do in the game that are simply so awful that they'll lose it and try to take you out because you're such a monster. Charon's contract will prevent him from taking action against you, but if you release him after having crossed the horizon, he'll immediately turn on you and try to kill you. This is a game where you can be so horrible of a person, your own friends will turn against you and try to murder you.
Harlan Wade from F.E.A.R. indisputably crosses the MEH when he sends his pre-teen daughter into the lab of the company that he works for so that they can conduct experiments on her psychic abilities. Later on, Wade decides to place Alma in a permanent coma and have her impregnated with the hope of creating first a super-soldier, then a psychic commander of a battalion of mindless soldiers. Finally, he just has the plug pulled on her. The Big Bad's murderous rage that leaves dozens or hundreds of civilians dead is a bit understandable after you learn all of this.
Golbez subverts it. His atrocities throughout the game would count except he was being manipulated by Zemus and is clearly remorseful for his crimes, taking full responsibility.
In Final Fantasy VI, Kefka is introduced as more of a nuisance, but a general of the enemy Empire nonetheless. His clownish charm fades rather quickly, however, after he disobeys direct orders and poisons Doma's water supply. The situation up to that point: General Leo had Doma Castle besieged, and was likely to win in just a matter of time with minimal casualties. Some time after Kefka arrives, Leo is summoned back to Vector to meet with the Emperor. Now there's no one to stop Kefka from dumping deadly poison into the Doma River, killing absolutely everyone in the castle; men, women, children, and Imperial P.O.W.'s that he knew full well were still trapped inside. The kicker here, which cements this act as Kefka gleefully tapdancing and cackling his way across the Moral Event Horizon, is that the Empire was going to win anyway. There was absolutely no possible justification for this heinous war crime other than Kefka wanting to hear "the music of hundreds of voices screaming in unison".
His only excuse at all for all this? As an early magitek knight, the process very likely drove him insane. No, that doesn't cut it.
Emperor Gestahl, while not nearly as evil as his subordinate Kefka, still crosses the line when he is shown in a flashback to have orchestrated an invasion of the Esper world. While the invasion ends in failure, at the end he discovers an infant half-esper, and rips the baby from her mother's arms, killing the woman in the process, while gloating about how he's going to subject her to a life of experimentation. Oh BOY.
Note that in the original SNES translation of the game this is somewhat softened; Madonna actually asks Gestahl to take care of Kefka (which doesn't explain the thwack he still gives her afterwards, however). This was most likely due to Nintendo's Never Say "Die" policy at the time rather than a change or error on Ted Woolsey's part.
Of course, the Turning Point of the game, when Kefka causes a cataclysm when he intentionally moves the statues out of sync on the Floating Continent, more than cements his status as not only an evil person, but a usurpingBig Bad, as well.
Sephiroth (pictured at the right) in Final Fantasy VII is initially shown to be quite sympathetic despite Cloud's hatred of him. He saves the party at Shinra HQ and seems to be working against the Evil Corporation finding the Promised Land. Even during Cloud's flashback, when you discover that he's not human (his Mom, Jenova, is actually a feminine alien in a tank), he remains worthy of pity. But then he goes crazy and burns down Cloud's hometown, killing Cloud's mom and Tifa's dad among others, as well as almost killing the devastated Tifa when she lost it and tried to take revenge for her father. And if that wasn't enough of an Event Horizon for you and you're still somewhat willing to feel sorry for him, there's always the part where he murders Aerith (also pictured at the right).
President Shinra and Heidegger ordering the destruction of a sector of Midgar just to get rid of some terrorists. The Turks (mainly Reno and Tseng) might have crossed the line too by actually carrying out this heinous order.
Then there's Scarlet leading mass murder via the complete destruction of the town of Coral.
And Hojo. Where do we start with Hojo? Injecting alien cells into his unborn child? Murdering Professor Gast right in front of his wife Ifalna and his child Aerith, whom he then kidnaps for horrible experiments? Doing more horrific experiments on Vincent, Zack, and Cloud? Also being indirectly responsible for Sephiroth's descent into insanity as well as Sephiroth's aforementioned murder of Aerith? You might as well assume that he crossed the line right at very beginning of his career. Taking the Expanded Universe into account, Hojo's life seems to consist of finding new lines to cross and gleefully leaping over them like he was practicing for the long jump.
Judge Bergan's rampage on Mt Bur-Omisace in Final Fantasy XII, in which Imperial troops murder unarmed refugees, their guards, and priests indiscriminately, and follow up by killing the Gran Kiltias Anastasis. Putting Bergan down like a rabid dog immediately after finding out is very satisfying.
Gharnef, who starts by murdering Linde's dad, Miloah, due to jealousy for not inheriting Aura, and later not only manipulating Emperor Hardin and getting him Brainwashed and Crazy, but kidnapping and brainwashing Elice, Nyna, Maria, and Lena so they'll be Human Sacrifices for Medeus. And the newest games add another one: brainwashing Eremiya when she was right in the lowest point of her life, then having her raise Tykebombs for him... and once she loses the fight against Marth's group, he debrainwashes her only to mock her and have her die in despair. Eremiya was a total bitch, but not even she deserved that! Especially since Gharnef made her that way!!!
Lang is revealed as early as the first chapter to commit a wide variety of atrocities, including robbing from civillians, taking away young girls (undoubtedly for a gruesome fate), planning to slaughter the families of those who rebelled against him, and kill the young heirs of Grust.
Despite being a Well-Intentioned Extremist, Arvis crosses this in Chapter 5, wherein he throws a party for Sigurd, who has all but cleared his name. That's not the MEH; what happens at the party is. He basically brings out his new wife, Deirdre, who was Sigurd's wife before she was brainwashed, to mock Sigurd, laughs at him for his naivety, and then has a group of mages drop meteors on the entire party — which, by the way, includes his younger brother."Arvis, you dastard!" sums it up pretty well.
Like Arvis, King Travant is a Well-Intentioned Extremist who just wants what's best for his country, but it's hard to like him after he tracks down and kills Quan, Ethlin, and half the Lenster knights, then kidnaps baby Altenna so he can have the Gae Bolg.
Hilda, resident Lady of Black Magic, looks like she crossed this in the story by hunting down and killing children... but then you learn that she actually crossed it long before the second generation started. Her husband, Blume, had captured his sister Tiltyu and her daughter Tinny (who couldn't have been more than four or five at the time) and brought them back to Freege. So what does Hilda do to them? Spends several years torturing Tiltyu to death while making Tinny watch. And once she was done with her sister-in-law, she began to abuse said girl further. Upon learning this, Hilda goes from being just an unpleasant boss to someone you REALLY want to kill.
Ephidel having cute-as-a-button Leila butchered, and watching it with that perpetually-irritating smug grin on his face. Interestingly enough, he just gave the order; the character who actually did the butchering, a Tyke Bomb raised from infancy into a brutal killer, pulls a Heel-Face Turn and ends up as one of the most sympathetic in the game!
Sonia making the revelation that she killed Nino's real parents, that she never had any care or love whatsoever toward Nino, and then attempting to kill Nino herself. When the adorementioned "butcher" witnesses such stuff, this is the push he needs for his Heel-Face Turn.
It's followed by Nergal giving a kidnapped Ninian a brutal Hannibal Lecture in which he browbeats and verbally abuses her into reverting to her Dragon form, setting her loose so she would be slain by Eliwood without him knowing it (and under the control of the Durandal sword, made for killing dragons), and then not only revealing it to Eliwood as Ninian dies in his arms (throwing Eliwood into a state of utter despair), but laughing about it. Did we mention that it's all but stated that Ninian is his long-lost daughter? Not even the fact that he lost his memories is good enough to get him off the hook for that, considering his glee when he tells Eliwood that he's fatally injured the girl who loved him.
Mad King Ashnard, Big Bad of the first game, pumped Rajaion, prince of the dragon laguz, full of a Psycho Serum that both drove him insane and mode-locked him into his dragon form, then used him as a mount — all after using his pregnant sister as bait to lure him in (he then abadoned their son).
Izuka, Ashnard's chief scientist, is the one who developed the aforementioned Psycho Serum. In the second game, he actually joins your party as your (laughably incompetent) strategist, during which time he uses his drug on Muarim, though he is thankfully cured. After that, you want him dead, and it's no shock when he's revealed to be working for...
Lekain, easily the most horrible person in both games. To say nothing of the fact that he hands out Blood Pacts like candy, this lovely fellow bumped off his country's beloved empress, framed a race of Actual Pacifists for the crime, then whipped his countrymen into a genocidal frenzy, in the aftermath of which only four of said race were left. The Reveal that he was one who gave the order for the genocide immediately puts him in a separate class from the rest of the series' villains, and every named character clamours for his head on a pike.
General Jarod, Disc One Final Boss of the first part of the second game, treats a conquered country like his personal playground, casually committing atrocities everywhere he goes for his own enjoyment. The MEH probably comes when he has his men shoot a preteen boy in the back. Micaiah heals him, but still.
Duke Valtome may be hilarious, but that still doesn't change the fact that he sent his own men to almost certain death in a volcanic cavern just to check if the heroes were dead, nor the fact that he sics his goons on Elincia after she willingly disarms herself as a gesture of peace to him.
Duke Hetzel considers himself to have crossed this line for not standing up to the likes of Lekain and Valtome, but he is, if not sympathetic, certainly pitiable.
Finally, we have the goddess Ashera, who is considered to have crossed it in-universe after she resurrects a legion of zombies to fight the heroes. Even Yune, a goddess herself, was brought to tears upon witnessing this.
Validar has many MEH crossings under his belt. Having his having his own blood son/daughter, the Avatar, bred and raised as the prospect vessel of Grima is pretty despicable, but might be Evil Cannot Comprehend Good as he himself was also raised this way. Thus the worst one is murdering Aversa's whole family and brainwashing her into being his servant when she was a little girl, as revealed in spotpass content.
Driscoll from the first Front Mission stops being an aloof and seemingly not-so-evil enemy commander and does a triple sow-cow past the point of no return when it's revealed that, after nearly half a game of searching for her, he had the main character's fiancé killed and her brain converted into the CPU for his custom wanzer.
The Locust from Gears of War were nasty in the first place, but just in case you thought that they might actually be justified in their extreme actions (as Myrrah continually tries to pass them off as being), they skip gleefully past the Moral Event Horizon in Gears Of War 2, where they're revealed to capture humans just so they can expose them to torture so nasty, the biggest Badass of a game series that's practically Made Of Badass commits suicide once he's freed.
The reason Tai commits suicide is his religion believes that the soul can leave the body before death, and this is what happened during the torture. After he was free, his body was soulless, so Tai saw no point in having earthly remains.
Golden Sun has Saturos and Menardi, whose plan is to revive the forbidden power of Alchemy so they can take over the world. However, their goals are noble, though never explained until the second game. The duo are actually out to save the world since the sealing of Alchemy turned the world into a literal Flat World and is crumbling away into nothingness. The pair tried to talk to the elders of Vale about the situation, but they were ignored and told that Alchemy should never be released. Desperate to stop the destruction, Saturos and Menardi brute force their way into the sanctum to steal the Elemental Stars needed to power up the Elemental Lighthouses to restore Alchemy. It's presumed that the pair would have used the newly released powers to conquer the world anyway and their successors, Agatio and Karst, would have done the same thing.
The sequel has Blados and Chalis as well as Alex cross this in the middle of the story by activating the Grave Eclipse, covering half the continent in darkness and leading to thousands of innocent deaths. Probably the worst part about this is that, unlike Saturos and Menardi or Argaito and Karst, they have no clear motive for this. For the Evulz is the best explanation.
In Ghost Trick, Commander Sith backstabs Yomiel by tricking his spirit into leaving his body for another part of the sub, removing the Temsik meteorite, and sinking the sub. This would condemn Yomiel to an eternity in crushing darkness, completely alone without even a body to move with. And his only reasoning is that he outlived his usefulness. Since we feel a little sorry for Yomiel by this point, it doesn't feel like karmic justice.
The Grand Theft Auto series, being obviously a crime-centered game and considering the great cynicism in its sequels, plays quite a lot with this trope.
Grand Theft Auto III: Catalina crosses this when she kills her boyfriends, purely interested in the thrill of violence and crime, not for love.
Grand Theft Auto: Vice City: Ricardo Diaz crosses this in the mission "Death Row", admitting to Lance Vance that it was he who killed Lance's brother and then sending Lance off to be tortured to death.
Sonny Forelli crossed this before the game's events. In the final mission, it is revealed that he set up the entire incident which landed Tommy in jail, with no explanation for why he did that being given, and after the entire drug deal went into a mess in the beginning, it is implied that Sonny set the deal to go to hell and wanted to have Tommy killed. This shows that he has no problem betraying his close friend and one of his most powerful men in his organization for no reason and shows no remorse for this. And it is likely that Sonny would have killed Tommy if he had given the money he made from his empire's operations.
Lance Vance seems to really cross this when he allied with Sonny and tries to kill Tommy. He doesn't even show remorse when he tries to kill Tommy, and you see that he does it with glee. For what it's worth, he was delusional enough to think that he was pulling the weight when he and Tommy were working together.
Grand Theft Auto: San Andreas: Tenpenny, Pulaski, and the Ballas in the video "The Introduction", killing CJ's mother so that he came to Los Santos and give him an easy scapegoat for Pendlebury's murder. And the worst is that they murdered him.
Tenpenny probably also crossed this in many missions, forcing CJ to kill people who want to discover their corruption, including FBI agents.
OG Loc absolutely crosses it when he ordered CJ to kidnap and kill the manager of Mad Dog, and as if that were not enough, also ordered him to kill all his guards and steal the rhyme book of Mad Dog to be made famous. It is incredible that an apparently comedic character and even ridiculed by their partners has become so vile, especially since later on Mad Dog is Driven to Suicide
Catalina, shooting civilians randomly in a betting house simply because she enjoys it. Even CJ himself was disgusted by Catalina.
Salvatore Leone has probably crossed it when he threatens CJ to kill him and his entire family, although not proven if he really did in later years.
Jerry Martinez crosses this when he kidnaps, rapes, and intentionally injures Louise.
Armando Mendez absolutely crosses this when he kidnaps and tortures (and allegedly rapes) Louise. She dies as a result.
Vic himself crosses the line when Louise convinces him to take over Marty's gang. Before then, he was either just trying to make a living or being threatened into it.
The Covenant from the Halo series have murdered BILLIONS. For an In-Game crossing, Halo: Reach is probably it, particularly during the mission Exodus, when they shoot down a ship that had 600 innocent people on it. After that, no one wonders why people have fun killing the alien jerks.
Hitman Absolution has Bigger Bad Benjamin Travis, who crosses it twice, first by masterminding a top secret and highly unethical project to create a new Agent 47, except this time around the clone is a 14-year-old girl. 47 sympathises with her and rescues her from her captors, prompting a huge manhunt culminating in Travis and his goons burning a town to the ground and massacring the inhabitants in a frantic search for 47. At this point you'll be wishing death upon the guy.
The North Koreans from Homefront gleefully race across it, as demonstrated in the opening level when they shoot a screaming child's parents and possibly shoot him.
The mass grave where all of the re-education subjects were systematically executed and put into a gigantic pile to be forgotten shows how much they cross it.
The KPA attack the Resistance base, and there are a large number of children in it, and they kill all of them.
The Survivalists cross it within minutes of meeting you.
Later, the KPA bombard the entire town as retaliation for the Resistance's attack on them.
In inFAMOUS, the player is given a karma choice. Either destroy the Ray Sphere and become a hero to all, or activate the Ray Sphere and become so evil that you can never be redeemed. You become irredeemable: the Karma Meter sets to its most evil setting and sticks there permanently.
Similarly, Zeke crosses it when he attempts to use the Ray Sphere to give himself powers, knowing it would kill thousands in the process, and then when it doesn't work, he ditches Cole to join Kessler. He gets better in the sequel, though.
In Injustice: Gods Among Us, Regime!Superman crosses this line when he burns a hole right through the skull of Regime!Shazam for daring to turn around on his word of a new world order. Granted, Supes had done a lot more prior, but when he does that, on top of giving orders to destroy Gotham City and Metropolis to punish the people that are siding with the Insurgency, it provokes Regime!Flash to pull a Heel-Face Turn.
This then becomes a moment of Fridge Horrorwhen you remember that Shazam isn't an adult superhero, like the rest of the cast, but rather a 10 year-old boy. Supes doesn't just cross the MEH, but shoots past it faster than the proverbial speeding bullet.
YOU can cross this in Jade Empire if you decide to bind Death's hand and bind most of your teammates as well.
In the Jak and Daxter series, Count Veger crosses this line when he gloats to the protagonists following Damas's death.
And in the second game, Erol crosses the line when he tries to run down Jak after losing both the big race and Keira. However, he winds up crashing into several barrels of Dark Eco and is blown up, but survives.
Kane and Lynch. Which character doesn't cross the Moral Event Horizon? Well, Lynch has the excuse that he's a complete psychopath, but even his psychotic episodes cross it.
The part where Lynch has a psychotic episode and shoots Yoko, effectively ensuring that Kane's family will be killed, definitely counts. Made even worse when, instead of apologizing or something, he refuses to take responsibility and yells at Kane for negotiating deals with the enemy.
Curtis Blackburn of Killer7 is a murderous sociopath, but hey, you're playing as a group of assassins. Then you see what he did to his ex-partner Pedro as punishment for getting in his way, and suddenly he becomes the worst person in the game.
Even before that, Curtis is known as a pedophile with a loli fetish and a penchant for selling organs on the black market. Although what happened to Pedro is one of the most gruelly frightening moments in killer7, he's crossed the Moral Event Horizon well before.
Killzone: Stahl is already quite nasty; he uses POWs as test subjects for his Petrusite experiments, and shoots an ISA prisoner just to show what it's like in Helghast. Then he destroys the Helghan fleet with his Petrusite weapons to show that he's in charge now, and plans to use it on Earth and possibly every other colonized world.
Ansem (actually Xehanort) definitely crossed this line in the original Kingdom Hearts when it was revealed that he experimented on living people just For Science!. And it was outright stated that the experiments caused their hearts to collapse! In this series, hearts are a Captain Ersatz for souls. So essentially, his experiments caused people's frickin' souls to collapse!
Master Xehanort may have did a lot of bad things throughout his life, but extracting the Darkness from Ventus's heart and creating Vantias (which almost led to the boy's death) really says a lot. But he may have already crossed it in his youth, when he travels into the future and shatters Sora's heart.
And don't forget the many various Disney villains throughout the series, though very special mentions go to Lady Tremaine, her two daughters, and Clu, all of whom are much worse than in their source films.
Rugal Berstein: Massacring Heidern's unit and his family, as well as putting out his left eye. And transforming the people he defeats into literal trophies. And beating Kyo's father within an inch of his life... to later get him Brainwashed and Crazy. The CD dramas and the Tatsuya Shinjyouji manga has him murdering his servants purely for commiting goofs like bringing him the wrong things, and in the Shinjyouji manga he also kidnaps Kyo's girlfriend Yuki to use her as the bait in a particularly cruel Deadly Game involving her, a time bomb, several phone calls, and the match between the Japan Team and the Women's Team in the streets of Osaka.
Goenitz: Aside from murdering Chizuru's twin sister Maki (made worse in KOF: KYO because in that continuity the twins are little girls and he's an older teenager), he subjected a pre-teen Leona to More Than Mind Control and made her kill her parents and her fellow villagers, solely because her father refused to re-join the Orochi clan. And in the KOF: G manga, he does that to her again. (Alongside killing thousands of people via merely showing up, and also beating Chizuru and Kensou within inches of their lives.
Yashiro, Shermie, and Chris: Revealing themselves as members of the Orochi Clan and becoming the sub-bosses. In the Sacred Team's pre-fight talk, add revealing that they plan to use the aforementioned Yuki as a Human Sacrifice, and mocking Kyo's anger and concern. It's even worse in the KOF: KYO game, because this is done in front of a restrained Yuki, whom they have been holding hostage for at least two days. (In the original game, they still had not gone after her).
Igniz: After going A God Am I, he plays the NESTS members like pawns and discards them once they're not useful, which includes more or less sympathetic figures like Foxy, Diana, Kula, Candy, and especially Nameless and Isolde. And once you defeat him, he throws what amounts to a cosmic tantrum and tries to pretty much destroy you alongside himself.
Ron, leader of the Hizoku: razing his own village and murdering a sizable number of his clansmen to offer his services to NESTS for reasons unknown. He's labelled as a traitor by the clan, and nearly every survivor of that massacre who didn't jump ship with Ron is now hunting him down for answers and retribution. (Including clansman Lin, clanswoman Luan, son Duo Lon, and illegitimate daughter Xiao Lon.)
Saiki: callously killing his most loyal and sympathetic servant, Mukai, right after he had offered to fight in his stead. And he follows it by taking over Fake Defector Ash's body to transform him into Evil Ash and keep fighting the heroes, much to Elisabeth and everyone else's horror.
In the beginning of Kirby Mass Attack, Necrodeus appears out of nowhere and soars through the MEH by splitting Kirby into ten versions of himself and killing all but one of them. To truly demonstrate the shock, this happens at the beginning of the game. It says something when your Big Bad can nearly kill the main protagonist while barely lifting a finger.
The ending of The Last of Us — due in no small part to the game's Grey and Gray Morality — has been something of a Base Breaker among those who have played it regarding which character involved crossed the Moral Event Horizon. The game hints that the fungus directly alters a host's brain, so when Joel and Ellie finally reach the Fireflies'headquarters, their leader, Marlene, reveals to Joel that the operation required to synthesize a hypothetical vaccine would inevitably kill Ellie. By this point, Joel has developed an essentially familial bond with her, and after she has ordered a troop to remove him from the premises, he kills said troop and proceeds to fight or sneak his way to the operation room. Upon arrival, he may or may not kill any or all of the surgeons present before carrying Ellie out, and killing Marlene when she attempts to dissuade him in the parking garage; effectively destroying current Firefly leadership and, given the fact that they were already on the defensive, possibly hampering any attempts of synthesizing a vaccine. At first, it would appear that Joel is clearly a case of Villain Protagonist. However: a fairly easily overlooked recorder on the upper level of the complex mentions that Ellie was not the first immune, and that they had operated on many in the past which did not yield the desired vaccine; only considering Ellie in that her case appeared to be different, and that she would possibly yield better results. This, added to the fact that many wondered whether a vaccine was truly practical, especially given the cost of such a vaccine, led many to believe that Joel actually prevented yet another unnecessary death and that Marlene and her Fireflies were sacrificing too much. It remains a subject of heated debate, still.
Left 4 Dead has an interesting case of this. Bill is certainly no bad guy; however, in the third part of The Sacrifice comic, he refused to slow down the train for any survivors that were trying to get on, including a doctor that wanted to join them. Every survivor was horrendously eaten by the horde. Bill outright stated that anybody that's not in his group, alive or zombie, will not be saved. As expected, Zoey refuses to be even near Bill afterward.
In Ocarina of Time, it's hard to tell where Ganondorf crosses this line, but it's probably at trying to have several Gorons fed to a dragon as a "warning" to those who would oppose him. Sure, killing the Great Deku Tree to steal what it was keeping from him, or deceiving the established authorities as a means of power, are evil actions, but attempting to massacre several members of a peaceful tribe when he GETS his power is far worse.
Averted with Ganondorf in The Legend of Zelda: The Wind Waker, where he is far less evil than in some other games in the series. When Link and Zelda attack him, he grabs a hold of Zelda, raises his sword to cut her head off... and then changes his mind and slaps her unconscious. Granted, a man who's like eight feet tall hitting a girl in the face might be a moral event horizon for a minor character, but this is the Big Bad we're talking about. His decision to spare her costs him his life when she and Link then kill him.
During this same pre-battle scene, Ganondorf also explicitly tells Link that he will spare him, as he only needs the Triforce piece the hero carries. Once he takes it, he combines it with his own and Zelda's, summoning the full Triforce to grant him one wish. And this wish? To raise the sunken Hyrule back up above the waves and let him rule it. You might have expected him to be all "yar har eternal shadow", but judging by his earlier speech, he genuinely just wanted a nice country for his own people instead of the harsh desert he came from. It's not until the King of Hyrule shows up to steal the wish that Ganondorf goes truly Laughing Mad and Axe Crazy on the heroes.
Zant in Twilight Princess crossed this line in a similar manner when he executed Queen Rutela in front of the Zoras for standing up against the army of the Twilight Realm.
Subverted in A Link Between Worlds with Princess Hilda of Lorule toward the end when she reveals that she had been manipulating Link in order to restore Lorule to its former glory by stealing Hyrule's Triforce, since Lorule's Triforce was destroyed by her ancestors, then sends Yuga to kill him. Fortunately, Ravio comes back in time to make Hilda realize what she had done.
Yuga, however, crosses it further when he reveals that he never actually cared about Lorule, that he himself was manipulating Hilda and plots to bring further destruction.
Seedle's backstory revealed in the last episode of Makai Kingdom even has several Overlords pissed with him. Put quick and dirty, he (an allegedly noble samurai) raped Salome (who fought back and killed him), and she was burned at the stake for slaying a hero; he thinks it's not enough.
The Mass Effect series tends strongly towards ambiguity, but there are still some cases where a line to ultimate unredeemable evil is crossed.
Even though he can be seen as not responsible for his actions in Mass Effect, one optional dialog reveals that Saren crossed the line a long time before any of that. While on a mission with Anderson, he destroyed a refinery, killing hundreds of civilians, then attempted to frame Anderson for the operation's failure because he didn't want the council to induct a human into the Spectres.
The Collectors in Mass Effect 2 are pretty evil, but most of the time, they simply emotionlessly capture paralyzed humans and bring them to their ships. But at their home base, they melt them alive with nanites to harvest their organic components as a building material for a new Reaper. The Collectors aren't really the ones responsible, however. Harbinger, the Reaper controlling them, was.
In Overlord, Dr. Gavin Archer forced his own autistic brother to take part in a traumatic experiment. The paragon interrupt is a gunwhip to the face. Then again, he is shown in Mass Effect 3 to have defected from Cerberus, and also made sure to destroy what was left of Project Overlord in the process. He also out and out told the Illusive Man that, "if he wanted the devil, all he had to do was look in the mirror".
Cerberus has been shown to be completely ruthless in their research projects throughout all the games, which often resulted in heavy casualties from escaped experiments, and they were never above murdering anyone who started to know too much about their activities. But in Mass Effect 3, they drop all pretense and secrecy and straight out murder any witnesses. That's not where they cross the Moral Event Horizon, though. The final line is on Sanctuary, where they set up a refugee camp to get new supplies of humans to be turned into mind-controlled cyborg soldiers. Everyone who doesn't fit the specifications gets turned into Husks to become live targets for new anti-reaper weapons.
Another example from the third game: Quarian Admiral Han'Gerrel vas Neema is willing to destroy the geth dreadnought despite the fact that Shepard and Tali / Xen are still aboard, and later can potentially doom his race all because of how much he wants to destroy the geth.
Even a pure Renegade Shepard seems to have defintiely crossed this line by Mass Effect 3. Fans of the series will argue over how evil his/her questionable deeds over the first two games were (the usual list includes killing Wrex, the Rachni Queen, Gianna Parasini, Aresh, and Samara, and leaving civilians to vaporize/burn to death in order to get Balak/Vido Santiago). However, all of those things could be seen as at least somewhat justified, both by in-universe characters and by players. What really seems completely monstrous and unjustifiable in the third game is if Shepard murders Mordin/Padok Wiks to sabotage the cure for the genophage if Wrex is the clan leader (or, to a lesser extent, if Wreav is the clan leader and Eve survives). To make matters worse, if Wrex is the clan leader, he will confront Shepard about it later. Shepard will attempt to lie to his face and either kill him or have C-Sec gun him down. After all of that, even Shepard seems to think he/she crossed the line.
Special mention should be given to not only allowing Samara to commit suicide to avoid having to kill her one remaining daughter in her mission in 3, but then killing said daughter yourself. Not only is it evil, it's completely unnecessary.
This happens in Mega Man Zero 3, when Copy-X and Weil destroy a human residential area to capture the Dark Elf. Though Weil was Obviously Evil upon his introduction, Copy-X's previous actionsnote Heavy discrimination against and "retiring" innocent reploids to conserve energy so human society is mostly unaffected by the recent energy crisis were a bit more morally ambiguous up until now. At this point, Harpuia can't stand it anymore and defects from Neo Arcadia. A bit later, when Copy X and Weil contact the resistance to cooperate, Ciel cites this event as why they can't be trusted.
Colonel Volgin is small time compared to the one behind most of the Metal Gear Solid series, Major Zero. Although his status as a villain is only revealed in the final (for that storyline anyways) game, when it is, the implications of so much of what this man has done becomes apparent. Not only did he create a shadow organization meant to control every facet of human life, but he created a system meant to completely subjugate and ultimately enslave humanity in a cyclical hell of controlled military conflict for generations to come, simply because he felt sour about bitter differences between himself and Big Boss. And on top of that, he attempted to destroy and manipulate his former friend with a variety of despicable tactics, such as threatening and manipulating a Costa Rican-American girl to become a crazed agent and saboteur in order to destroy Big Boss' reputation. It was also enough to cause Kazuhira Miller, who briefly worked with Zero as a means to expand MSF, to have quit working with him out of disgust for nearly ruining MSF (though, the bit about Miller is merely implied). It's uncertain where exactly Zero crossed that moral event horizon, but he certainly did. So did most of Big Boss' former "friends", save Ocelot and EVA.
In Metal Gear Solid: Peace Walker, it's revealed that Hot Coldman set up what happened in Metal Gear Solid 3. In other words, he's the reason The Boss got killed, because he feared her growing influence. He's also indirectly responsible for Major Zero's fall as well. Worse is that he shows absolutely no remorse for what he did and a little glee. If that's not enough, he also instigates a nuclear apocalypse again, and it is implied that he was the one responsible for the butchered AIs in 4 (Coldman makes some statements that parallel the AIs forsaking The Boss's will when developing the War Economy).
In the first Metal Gear Solid, Liquid Snake is an evil son-of-a-bitch from the beginning, but the kid gloves are off when it's revealed that he was impersonating Master Miller after having him killed.
Solidus Snake crossed it in Raiden's backstory, where he is revealed to be Raiden's parents' murderer, and just to rub salt in the wound, turned Raiden into a brutal Child Soldier that later results in him being a psychological wreck.
And the latest addition is Skullface on Metal Gear Solid: Ground Zeroes, a sadistic freak who crossed the MHE with flying colors by serving as a chief torturer on the Guantanamo Bay Detention Camp, amongst his actions are implicitly scorching a man to death, brutally beating, whipping, crippling and raping Chico and Paz, destroying Mother Base through a sneak attack that killed almost everyone and sending Big Boss into a coma only to wake up nine years later to see his life threatened a second time by this lunatic's XOF Unit.
Mushihime-sama Futari brings us Queen Larsa, who goes psycho-insane after learning that her older son Aki has been killed, and sends her army out to kill Reco, who accidentally murdered him in the previous game. Sounds like typical Mama Bear tyrant fare. Then there's her younger son, Palm, who, while understandably upset by his brother's death, believes Reco to be a good person and that Aki's death wasn't her fault. How does Larsa react to this? She disowns him and leaves him to die. And tells him he can be replaced. If you make it to her as Palm, she tries to kill him — although she is a shmup final boss, that she would try to kill her own son — at FULL STRENGTH, no less — says something about how little she cares for anyone other than Aki.
In Myst IV: Revelation, Sirrus kidnaps Yeesha for Grand Theft Me purposes and boasts to her of his plan.
In the novel Book of D'ni, Ymur is another Woobie, Destroyer of Worlds until he tries to become the new Master, in the same barbaric vein as the Terahnee enslaved ahrotantee.
Saavedro — and you — can cross the Moral Event Horizon in various endings of Myst III: Exile. If you lower the outer shield when Saavedro says to, he says "time to keep my end of the bargain" — and throws the fucking Releeshahn Book away before setting off. Later, if you get the Book from him, you have the option of leaving him trapped with no way out. Atrus calls you out if you do this.
An evil Player Character in Neverwinter Nights 2 usually comes across as a Card-Carrying Villain or a brutish thug, and doesn't really get an opportunity to do anything truly evil... until the end-game. Then it becomes a question of not "did they cross the line", but "WHEN did they cross the line". It could be when you quite cheerfully turn on all your former comrades, brutally kill them, and then bring them back to life as twisted undead so they can serve you and the King of Shadows forever. It could be when you lead legions of demons and the undead against Neverwinter and turn half the Sword Coast into a Crapsack World. Or it could be when you capture your foster father after he sets out to avenge you, torture him to death, then bring him back to life so you can do it all over again for your personal amusement. And the worst part is that everyone remembers you as a hero, because they didn't recognize you when you conquered them and thought you'd been slain by the "new general" (you) because s/he had your sword and cape..
Ammon Jerro crosses the line when he violently murders his granddaughter Shandra, because she tried to stop him from killing you. It's especially notable in that your other two Token Evil Teammates, a sociopath and a Social Darwinist respectively, will be outright disgusted by the act if they're present. Hell, Ammon himself will admit what he did is irredeemable if you confront him about it.
Myrkul, former god of the dead, in the expansion pack: if he didn't cross the line when he created a soul-eating wall to send "the Faithless"note those who don't worship any gods to, he crossed it when he used it to create a soul-eating Eldritch Abomination out of Akachi, his own High Priest, because Akachi tried to save his lover from the Wall.
You can cross the line in the same expansion (which Retcons the evil ending of the original campaign) by eating as many souls as you can to turn yourself into a god-killing Humanoid Abomination, including the souls of your companions, and then going on such a massive killing spree the gods themselves decide to step in and stop you.
Ninetails from Ōkami has all the marks of a very cool villain: sly, sneaky, Evil Counterpart to Ammy (even has his own Brush Techniques... with nine tails!) and an awe-striking battle. All of this is negated by it horribly murdering the innocent, beloved priestess Rao and stuffing her body down a well in order to deceive the populace, Ammy included. And then, once it had accomplished its goals, it drove Queen Himiko to her own death.
Strega does this throughout the game. Chidori is the only one who manages to pull a Heel-Face Turn(and she dies as a result). Takaya is the worst of the three, killing one of the most beloved characters in the game. Oh, and did I mention that said beloved character is also a major Stoic Woobie?.
In Persona 4, Adachi takes things even further. The death of Mayumi Yamano could be chalked up to accidental manslaughter, considering he didn't know people who fell into the TV world would die. The death of Saki Konishi, on the other hand, was no accident. To cover his tracks, he tricks Yamano's lover Namatame to carry out his dirty work, all the while trying to throw the Investigation Team off his trail. And for what reason? Because he's bored of working in a quiet rural town and is looking for kicks.
Less bloody but still unforgivable are the killing of Hijiri and the massacre of the Manikins from Shin Megami Tensei III: Nocturne — the first definitely cements Isamu's transition into The Sociopath, and the latter demonstrates the depths Chiaki is willing to sink to in order to gather power. The possible battle against Futomimi may also qualify, as you are essentially breaking his spirit by fighting him instead of helping repel the invading angelic forces.
General consensus is that Tayama's is the worst of the lot. He'd actually already crossed it before the game even began, but we don't learn precisely what he did until about halfway in. He distributes a drug called Red Pills to Tokyo's demon population to keep them from eating humans, and it's ultimately discovered that they're made from human brains; specifically, the brains of people who have been raised since childhood to produce the drug and who are given all the accommodations of livestock. Notably, every single character in the know about this, whether Law, Neutral, or Chaos, is grossed out by Tayama's actions.
The Archangels cross when they order the execution of everyone who has read the books distributed by Lilith. It might seem like Necessary Evil at first, since the books turned those who read them into bloodthirsty demons, but Lilith reveals that they do no such thing; they're ordinary books that present an alternative to the classist system the people of Mikado live in, and the people's newly-awakened rage at said system is what initiates the transformation. It could be argued Abbot Hugo shares in this since he carries the orders out, but he's plainly being jerked around by the Archangels, and he's just as much in the dark as everyone else.
Planescape: Torment. The game's plot revolves around the Nameless One trying to figure out exactly how you redeem yourself for committing one of these. Exactly what he did is never revealed, but it was sufficiently morally damning that a lifetime of nothing but saintly deeds could not make up for it, and in the end, he has no choice but to suffer penance for it in the Blood War. Except that in the end, he does have a choice — he can end his existence entirely, or just continue eternal life in ignorance, instead of dying. The best ending of the game is the Nameless One choosing to pay his penance... because, in a way, choice can change the nature of a man.
Given the sorts of horrible things you can do within the game if you so choose, whatever your original crime was must have been really awful.
Pokémon Black and White: Ghetsis, Ghetsis, Ghetsis... why, oh why, did you have to base your parenting off of Super Hero Aurum? You neglected your own boy, left him amongst abused Pokémon to ruin his perception of the world, raised him to believe Pokémon should be separated from humans, and gave him control over a group that only knew of his ideal. But that you'd abandon your kid after his failure to perform, call him a blasphemy upon mankind for the very way you raised him, and go against everything you ever taught him just for self-profit? Yeah... you can rot in jail for the rest of your life.
Black 2/White 2 reveal that N is not even Ghetsis' biological son. He's just some orphan/runaway that Ghetsis found one day and decided might be useful to him in some way.
In Black2/White2, it got worse. He has Kyurem in his possession, has it placed inside a machine and tortured so that it's power can be channeled through the Plasma freeze canon, which Team Plasma uses to freeze over half of Unova. Ghetsis' plan is to threaten to freeze the entire region in order to extort power and control from the masses terrified for their lives and health. To keep Kyruem in line and make it comply with Team Plasma's acts of terrorism, he physically and mentally tortures it with the Mind Control technology in his cane. When he takes Kyruem to the Giant Chasm in order to boost it's power, the player character interferes. So what does Ghetsis decide to do? Order Kyurem to attack the Kid Hero directly with a Glaciate attack, intending to freeze him/her alive or to death. So not only is he showing he Would Hurt a Child, but he's not even bothering to follow the conduct of Pokemon battles, preferring to have his super-powered monster lay a direct fatal attack on the kid! And he hopes that he/she will die in a state of despair and hopelessness, knowing that they've failed and he has won. This above all shows that Ghetsis is a sadistic freak of nature.
On the subject of that place, Ghetsis is running neck-in-neck with the Cipher syndicate both in terms of horrific deeds (which we're discussing here) and the potential for the continuation of such horrific deeds. See the main Pokémon Colosseum page for the further gruesome details on Cipher's many sins.
Arguably, Wheatley had one when he throws Potat OS into the elevator, then beats you down into old Aperture.
Another potential Moral Event Horizon, if that one didn't do it for you, is The Part Where He Kills You.
Or earlier, when Wheatley starts testing you, despite all your plans for escape.
All of these are justified. Wheatley was not in his right mind when he did all of this. GLaDOS's body corrupts the core attached to it to do rather extreme things. When you detach him in the end, he apologizes after the credits, wishing he could take it all back.
Prototype has the real Alex Mercer cross this the moment he unleashed the Blacklight virus on Manhattan just because he is cornered at Penn Station by Blackwatch. The virus itself, born from his death when it animated his corpse, is horror-struck by the sheer vindictiveness he displayed.
Psychonauts: As if Doctor Loboto wasn't bad enough, he crosses the Horizon by forcing Sheegor to steal more psychic brains for him by threatening to cook her pet turtle, Mr. Pokeylope (who's extremely intelligent and has a brain the size of an average human), if she doesn't. The exact moment: "Well, maybe I'll just make a cup for myself."
"It's made of turtles. Turtles that YOU LOVE!"
Kyoji Nanba of Racing Lagoon gets depressed as he's defeated by Sho Akasaki (you) and loses his chance to race in the Yokohama GP. He then takes a diablo-tuned car and gets himself killed.
Many, MANY, characters cross this line in the Ratchet & Clank series, especially Courtney Gears, Gleeman Vox, and Cassiopeia. One character, Emperor Tachyon, has been over this line since his own BIRTH, because his species are Always Chaotic Evil.
In Red Dead Redemption, Edgar Ross, when he's first seen in the opening cutscene, merely seems to be a bureaucrat making John hunt down his former gang members. When you finally get ahold of Escuella in Mexico, he definitely seems to be an awful individual, especially since he is the one imprisoning John's family. When dealing with him personally in Blackwater, he continues to build his jerkass points for every second he's onscreen, constantly insulting and mocking John, and at one point shoving a gun into John's stomach just to remind him that he can do whatever he wants, and John can't do a thing about it. However, once John takes care of all of the former outlaws he ran with, Ross lets him go, and John is finally allowed to return back to his family, who is unharmed. But... when he really crosses the line is when he orders the army to assault Marston's farm, culminating in John's death. Before this point, he was simply a thoroughly unlikable man who hated John. After this, he crossed the line.
Return To Krondor starts off with Bear and his pirates killing off a ship full of priests to steal treasure and one special object. If this does not qualify as a Moral Event Horizon, then the next few parts will. Bear attacks a bar and kills a young barmaid (it may have been worse than that), leaving the barowner without a daughter. He attacks a jail just so he can personally kill a small-time pirate who decided he needed to get out of the business. He cut down half the Krondorian guard squad. The guard captain is Bear's cousin. The guard captain wants to keep that fact a secret and he really wants to take Bear down. He sets an orphanage on fire when he is unable to escape the city through the gates. He escapes through the sewer, tearing through the Mockers (the Guild of Thieves) who got in the way. Bear accomplished all this in the first couple of levels. It seems that he that he not only crossed the Moral Event Horizon before the events of the game, but he sprinted through it and never looked back.
Saints Row has several of these crisscrossing one another, on both your side and the side of the enemy gangs and police. Julius blowing you up. Shogo ordering the interrogation and death of Aishia. Johnny Gat burying Shogo alive for it. Mareo and Jessica having Carlos strapped to the back bumper of a truck and dragged through the street face-first. Mr. Sunshine getting everyone's attention by macheteing some poor bastard in the back as he listened to music. Dexter selling out to Ultor and trying to kill you numerous times. Mr. Sharp killing Lin. STAG staging a terrorist incident, then trying to blow up Steelport. Killbane snapping Kiki's neck right in front of her twin sister. But the Boss, being the player character, gets the most. The Boss kills Jessica by making her boyfriend mistakenly drive a monster truck over a car she is trapped in, crippled the hand of a musician and tattoo artist whose only guilt was by association, manipulated an otherwise innocent Donny over the course of two games, shoots Julius, gets involved in human trafficking, has the option of weaponizing a zombie virus, and can in one game ending take over a city and make it secede from the United States, which will no doubt bring retribution down on everyone they know and the innocent civilians living there. These are not nice people we are dealing with, here.
Fuminori Sakisaka, if he decides he has no qualms with eating human meat. Just listen to him when Kouji comments to him on his cell phone about becoming "quite the meat eater":
Fuminori: "Actually, I've only killed one so far", Fuminori replies unapologetically, with perfect cheerfulness. "I've taken apart three or four, though. I've gotten pretty good at cutting the tendons and draining the blood and such."
Fuminori's line-cross is even worse: The player chooses whether he goes through with it, in one of TWO moments in the entire story.
Another option for the player to cross the horizon: using a PlanetBuster in Sid Meier’s Alpha Centauri. Using one will put you beyond redemption in the eyes of the rest of humanity (unless you repealed the UN Charter), and trigger a round of Gaia's Vengeance from an already contentious ecosystem. Made even more noticeable because not only will the Planetbuster obliterate its target, it will probably level the entire continent it hits, leaving nothing but a giant crater, as a personal reminder to everyone, and yourself, what a bastard you are.
"For the pain that I've caused you, I deserve no mercy. Even if it was to save mankind, it was too deep a sin."
Right in the first level of Singularity, you read some notes and hear recordings that suggest that the Big Bad had done some highly unethical things in the 50s. But all of that is off screen and only (strongly) implied. When you meet him at the end of the level, your partner demands to be treated according to the Geneva convention and to see someone from the United States embassy. The Big Bad coldly shoots himin the face.
In Skies of Arcadia, Lord Galcian gains the ability to destroy any or all of the lands underneath the Six Moons. To display his newfound power, he summons the Rains of Destruction from the Yellow Moon. What is underneath the Yellow Moon? Valua, the most technologically advanced land in Arcadia, and it just so happens to be Galcian's homeland as well! Galcian figured that if the most powerful country in the world could be reduced to ashes in no time, the rest would fall to him. What is amazing about this is that the Valuan army, the army of the country that he just wiped off the map, continue to stick with him, as Galcian is that much of a Magnificent Bastard.
And there is also Neyla in Sly 2: Band Of Thieves, when she betrays the Cooper gang and Carmelita Fox, and has them all (sans Bentley) thrown in a gothic dungeon.
Sly 3: Honor Among Thieves: General Tsao crosses this line when he captures the Panda King's daughter and forces her to marry him, despite her pleading to be released. His views on women really help him cross it.
Did you fail to collect all the Chaos Emeralds at the end of the Game Gear version of Sonic the Hedgehog 2? If so, then Tails will be held prisoner indefinitely by Dr. Robotnik, where he will presumably be killed, or worse. Definitely not something we'd expect from the Robotnik we know from the games.
Robotnik's entire schtick is doing horrible things to the happy critters of the forest, that's why all the machines Sonic destroys pop, and then critters escape the wreckage. Capturing Tails is only worse because Robotnik does all that other stuff without having a personal vendetta against his victims; God only knows what he'd do to his nemesis' only living friend.
Tikal's father Pachacamac crosses it in Sonic Adventure. Through the flashbacks, we are told that he wanted to use the Master Emerald to turn his city into a utopia. To get it, he storms the Emerald shrine with his soldiers, slaughtering the Chao there and attacking Tikal when she tries to stop him. He ends up getting himself and his men killed by Chaos by doing this, but also corrupts Chaos, causing him to become bitter and filled with hatred towards all life. It's pretty heavily implied that he's actually doing all this to use the Master Emerald as a weapon and build a Great Echidna Empire.
After all the killing he is responsible for, Black Doom has the balls to proclaim himself a savior of humanity, intent on saving people from their own errors.
In Sonic Lost World, the Deadly Six cross it when they activate Eggman's Extractor to drain the world completely of its energy, destroying it outright. They cross it a second time when they kidnap Tails to turn him into a robot, albeit by accident.
Soul Nomad & the World Eaters is a case where the protagonist crosses it multiple times throughout the entire Demon Path. By the end of the first battle, you've killed everyone in your village and before the death of a married couple, made it clear you wouldn't hesitate to kill their child too.
In Spec Ops: The Line, Capt. Martin Walker ultimately has to come to grips with the fact that he himself has crossed the moral event horizon. In fact, "The Line" referred to in the game's title is metaphorical, as Walker's actions result in the deaths of his squad members and many others. Had he just stopped at any point, all parties involved would have been better off. You could argue that the real moral event horizon comes when he gives the order to drop white phosphorous on enemy troops.
In Spider-Man: Web of Shadows, choosing the evil decisions lead to some prettymeanacts against the characters around you. But one thing that can particularly make the Web-Head cross the line is the dark option against Symbiote Wolverine: Spider-Man rips the Symbiote in half. With Wolverine attached to it. Let me repeat that: Spider-Man can cross this by RIPPING WOLVERINE IN HALF.
The Sorceress in Spyro: Year of the Dragon crossed the Moral Event Horizon when she reveals to Bianca that she doesn't want to keep the baby dragons in the Forgotten Realms to keep the magic alive, she wants to kill them all and take their wings for a spell to make her immortal.
"I don't have to kill them. It just stops them from wriggling too much.''
In Starcraft, there are a few. Arcturus Mengsk deploys a psi-emitter on the Confederate capital world of Tarsonis, consigning every life form on the planet (including over two billion humans) to death by the Zerg, leaving his right-hand woman Sarah Kerrigan to die in the process. Prior to Tarsonis, Mengsk had only deployed psi-emitters against Confederate troops. Letting the Horde of Alien Locusts eat your enemies? That's a Kick the Dog for sure, but could be justifiable. Calling said Alien Locusts to a planet with not only military forces, but with billions of innocents on it, and then sitting back and watching the slaughter? That's this trope. Kerrigan (very loyal to Arcturus) even calls him on it. Unfortunately, that causes him to decide that Kerrigan has outlived her usefulness, and leave her to the Zerg as well.
In Starcraft II Heartofthe Swarm, he was definitely beyond redemption when he ordered his fleet to fire on the Hyperion even knowing his own son was aboard!
It's hard to say if Kerrigan crossed it because it's unknown how much control she has over her own actions after being turned into a Zerg, but Infested Kerrigan's moment of crossing is when she betrays her allies and kills Fenix, just so she doesn't have to deal with him in the future (she also kills Duke, but he was an Asshole Victim.)
It was for Raynor. Indeed, one of the main plots of Wings of Liberty is Raynor finding a way to pull her back.
Samir Duran tricks DuGalle into thinking Alexei Stukov was a traitor, and leads DuGalle into having Stukov killed.
Stukov and DuGalle's meeting at the beginning of Brood War, over a hapless terran base overrun by Zerg, brought there by the UED themselves! It's debatable whether it was the crossing of the UED into the event horizon, since they hadn't done anything else yet, but it certainly showed you they weren't fucking around. The Power of Rock didn't save THOSE marines...
Even DuGalle knows they're crossing a line here:
Stukov: I know all about the Zerg, Gerard. We've all seen the tapes a hundred...
DuGalle: You've seen nothing! Studying a dissected Zerg in a lab is one thing, unleashing them on men is another! You must go into this with both eyes open. Are you prepared to go all the way with this, Alexei?
Star Trek Online has a number of characters who cross this line, very befitting of the series.
The first you encounter is Ambassador B'Vat, who seeks to bring a Forever War between the Klingon Empire and the Federation. How does he plan to do that? By finding and unleashing a Doomsday Machine (the same type from Star Trek: The Original Series) on the Federation. Thankfully, the player character stops that plan. He tries again by kidnapping Miral Paris, who is said to be the Klingon Messiah, dragging her to the 23rd Century, and using their future tech to alter time so that the Klingons ruled over the galaxy and restore the alterations of the Klingons at that time. He only succeeds in the first.
Before, there were actually missions where you could actually fail them and be deemed a traitor of the Federation. This has since been removed.
The biggest person who crosses this line? General Hakeev of the Tal Shiar. What did he do? Oh, nothing major, just be the reason that Romulus and Remus are now asteroid fields. Later moments include kidnapping innocent Romulans and Remans and performing experiments with Borg tech on them and capturing random people, including your player, and pitting them in Colosseum matches. Oh, and the reason he does this? Because he's working with the Iconians, a vicious race of aliens that are ready to take back the galaxy. Oh, and they crossed the line, too, by being the ones who gave Hakeev the means to blow up the planets..
In Star Wars: Knights of the Old Republic, right after you decide to follow the Dark Side path, the game makes it plain what an ultimately depraved monster you have chosen to become by allowing you to Force Persuade Zaalbar to kill Mission, his best friend, because she refuses to either join you or run away to save herself, and she's too nice to be brainwashed into going Sith herself. And Bastila compliments you for it. Mission is a 14-year-old orphan girl who by this point in the game has not only helped save your life at least twice, but whom you've taken under your wing as a surrogate daughter, and who at this point in time is the only member of your party still believing that you can be turned back to the Light Side. You get to hear her anguished cries of betrayal and disappointment as she dies.
And before all of this: Good luck repenting killing millions, if not billions of people during the bombardment of Taris, Malak.
In the first scene of Suikoden II where we see Luca Blight, he has just finished massacring almost all the members of a Youth Brigade camp (read: fantasy Boy Scouts) so that he can frame a neighboring country for the deed and get the people's support for a campaign of slaughter, rape, and pillage. He only gets worse from there.
In Suikoden V, the villains had toed the line between reasonable and malicious up until they sent assassins to wipe out the beavers, for no reason other than a desire to remove all ethnic diversity from the kingdom. After that, they were just plain evil.
And in Suikoden Tierkreis, the Religious Leader Valfred goes too far when he erases a country and his population, The Magedom of Janam, who was opposing him, with Manaril and Shams' family inside it.
Super Robot Wars Original Generation kind of... subverts this. Wilhelm von Juergen might've come across sympathetic. He simply couldn't bear the thought of being unable to protect his family and humanity from aliens, so he created a system that unites humanity by force. That may be stupid, but... good intentioned... wait a minute, what's that?! He just... killed Lamia out of cold blood, after he completely wrecked her physically, while she's battered and defenseless!? That's the last line of sympathy he can get. Forever, he shall be known as an unsympathetic Big Bad Wannabe.
Kyosuke's Evil Twin Beowulf crossed it big time during The Anime of the Game (Inspectors). His first on-screen appearance consists of him brutally slaying the Shadow Mirror version of Team SRX, ripping the SRX into pieces, and then he killed a defenseless Ryusei Date stuck in the destroyed R-1. All with a Slasher Smile on his face. He never did that in the actual game, and it does show that Beowulf is NOT heroic. At all. Rai had already died during the Black Hole incident, so someone else must've been piloting R-2.
Shikuu crosses it in Third Super Robot Wars Z: Jigoku-hen when he kills the pregnant Annalotta Stohls, causing the Geminides race to go extinct, as the mother is the one who spreads her genes.
The "Children of Tarrone" in the eighth mission of SWAT 4. Seems like your standard doomsday cult until you get to the basement and find that they willingly killed their children and tore up the concrete floor to bury them.
The Tales series is known for having sympathetic villains, so it's kind of shocking that Tales of Vesperia has two or three of the most vile, inhuman villains in the series.
First there is Ragou. The very first thing we learn about him is that he demands cripplingly high taxes from the people, and abducts the children of those unable to pay. Doesn't seem so bad, right? Well, then you learn that not only does he kill the kids, he feeds some of the corpses to monsters and sells the rest in the black market. And his reason for doing this? He was bored.
Not to mention that the people of Capua Nor can't pay their taxes because Ragou is using a blastia to control the weather, making it impossible for them to take their ships onto the water, AND he's ordered that any ship in the harbor be fired on if they try to go out to sea. Plus there's the fact that he tells the townspeople that they'll "never have to worry about taxes again" if they can obtain the horn of a monster roaming the countryside. Said monster is Ragou's pet, and he forces the people to hunt it, knowing that it will probably kill them, for his own amusement.
And then there's Cumore. Was there ever Cumore. At first, he only seems like a Smug Snake, but then he tells Leblanc right to his face that the Schwann Brigade is weak for showing mercy. Some time later, we discover that he has forced the people of Heliord in brutal labor camps very similar to WW2 labor camps. All this is topped off when it's discovered that he's sent countless people on a literal suicide mission, including one of his own men because he didn't load a prisoner wagon fast enough.
One could argue that Alexei crossed the line worse then Ragou and Cumore. First, he's responsible for most (but not all) of the previous two's actions. That alone makes him pretty evil, but then he orchestrates an attack on Nordopolica and has Flynn, Harry Whitehorse (The Don's son), and the Hunting Blades take the fall. This leads to one major Guild leader being turned into a monster that the party has to kill, Flynn and his brigade shamed, and tensions in the Guild Union rising to a boiling point, leading to the Don committing honorable suicide in order to both save Harry and prevent a civil war. Oh, and then we learn that he resurrected Raven against his will and forced him to be his slave/errand boy. And then, as the icing of a very vile cake, he forces Raven to kidnap Estelle, and then proceeds to Mind Rape her to such a point that he'd give Neon Genesis Evangelion a run for its money. Did I mention that the Mind Rape was so horrible that Estelle eventually lost complete control of her body (but not her mind), essentially making her a puppet for Alexei to control? Yeah, Vesperia pulled no punches in regards to pure evil villains...
In Symphonia, Rodyle crosses the Moral Event Horizon when he floods a passageway full of escaping prisoners, killing them all, in order to prevent the heroes from reaching the Mana Cannon.
Grand Maestro Mohs from Tales of the Abyss crosses the line hard. First, he manipulates two nations into igniting a bloody, pointless war, knowing full well that the losses would be through the roof, just because a prophecy of questionable legitimacy said this might bring prosperity to his own nation. This is only the tip of the iceberg, though, as we later learn that he kidnapped Anise's parents, and threatened to have them killed if she didn't act as The Mole to the party. The absolute worst thing he did, however, was forcing Anise to deliver her close friend Ion to him so he could murder him right in front of her. Oh, and Arietta, a member of the Quirky Miniboss Squad and another close friend of Ion and Anise, witnesses this as well and goes batshit insane because of it, forcing the party to kill her. Mohs doesn't care at all about this.
While he's not as reprehensible, the Big BadVan Grants crosses this himself by using Luke — someone who truly looked up to him, by the way — to destroy Akzeriuth.
An offscreen moment that's used to set up another character's backstory: it turns out that the destruction of the island of Hod was ordered by Karl VI, Emperor Peony's father, after he learned that Kimlasca intended to invade the island. This would simultaneously devastate the Kimlascan army, keep the valuable fomicry labs on the island out of their hands, and framing Kimlasca for the destruction served to very effectively squash anti-war sentiment on the home front. And all it cost was thousands of the lives of his own people.
LeChuck crosses it in a big way at the end of episode 4 of Tales of Monkey Island, when he stabs Guybrush in the stomach, killing him.
What makes this Moral Event Horizon even worse? He spent four episodes of the series lying that he was reformed, then, when he got the chance, murdered the person who was starting to consider him a comrade.
Before then, his sadistic torture of Guybrush in the final areas of Monkey Island 2.
In TaskMaker, the eponymous ruler assigns the player a series of Fetch Quests to claim various items throughout the land, and he rewards the player in some way after each item is returned. After the 9th task, the TaskMaker rewards the player with "DRUGS!!", a useless item that will send the player to Hell if used, and demands his final task — to kill a prisoner. Should you visit the prison, you'd find that the prisoner has a Good alignment, so killing him will cause the player to lose a lot of points and some Spirit. Returning to the TaskMaker after killing the prisoner will result in him mocking you, followed by a Game Over.
In Tears To Tiara 2 Abraxas releasing the King of Death marks the Moral Event Horizon. Before that The Empire was just trying to brutally crush a rebellion. After that, it was worse than genocidal. Abraxas was effectively trying to kill as many people as possible, regardless of who's side they are on.
In Terraria, the player character. In order to progress to the endgame, you must summon a boss in the Underworld, and in order to do so, you must murder the Guide with the Guide Voodoo Doll. As of 1.1, it's clear that death is not cheap for the non player character allies, as when they die, they are not resurrected, but rather replaced, and thus this amounts to murdering the Guide simply to progress in the game.
Wild Dog from Time Crisis really crosses the Horizon when he shoots Rachel and wounds her while she's fleeing from him, and while Miller cradles her wounded body, Wild Dog laughs as he starts fighting with Miller.
In Time Crisis3, the Big Bad of the Rescue Mission mode, Jake Hernandez, immediately crosses it during the first boss battle with him in the city. He grabs a young girl and an elderly woman and uses them as hostages. As for the elderly woman, what does Jake do to her? He throws her to the floor and kicks her on the back.
Megatron, in Transformers: War For Cybertron, warns the Autobots to leave Cybertron or be destroyed. When the Autobots began leaving Cybertron in spaceships, he has Trypticon blast them out of the atmosphere for no reason whatsoever.
Before that, however, was the arguably worse act of nearly murdering his entire world by infecting its sentient core with Dark Energon.
In the first game of the Trauma Center series, it's already pretty enraging that a fanatic unknown organization is threatening the lives of the innocent and the main character's beloved ones with their parasites for no good reason. But wait until the last part of the game, when you discover that they were making their experiments with GUILT on innocent children they kidnapped around the world! Add this up to some calculation: considering the speed at which GUILT kills the host, and the fact that the children were being used as incubators, with highly concentrated strains of the parasites, imagine the sheer number of kids dead in the hands of Delphi and you have a good example of Fridge Horror.
Screw you, Erika!. The exact moment for most people differs, but if you haven't felt she crossed it before, there's a line she says in the 6th Episode that hurls her across this line:
Erika: "I dashed all over the mansion, visited all the 'crime' scenes, and...completely severed their heads... All five people I killed......were very much alive and faithfully playing dead until the moment I killed them."
LezardValeth of Valkyrie Profile is one nasty piece of work and crosses the line many times (especially in the sequel/prequel), but very early on he crosses the Moral Event Horizon when he orchestrates the deaths of his former teacher, Lorenta, and her husband by giving the latter a potion that turns the drinker into a monster. Lorenta's husband begs her to kill him before he succumbs to its effect, but Lorenta can't bring herself to do it. He then turns into a monster and kills her. All of this was to draw the attention of the protagonist, Lenneth Valkyrie. Lezard claims he needed a sacrifice of lovers to lure the goddess to him and chose his former teacher because she and her husband had a "lifetime of love."
In The Walking Dead, Lilly crosses this when she murders Carley or Doug in cold blood.
Provided the player saved Doug rather than Carley, the scene plays out somewhat differently, in that Lilly's anger is directed almost entirely at Ben, and she is only annoyed by Doug's attempts at mediation. Eventually, she aims her handgun at Ben, who Doug pulls out of the way, taking the bullet himself, instead. Lilly is visibly horrified by the accidental murder, though it can still be argued as a Moral Event Horizon given it was still a result of Lilly's "guilty until proven innocent" attitude. However: no one who has witnessed her murder Carley considers her sympathetic.
Kenny crosses this if you side with Lilly in the meat locker. After Larry has a heart attack and Lee goes to help out, Kenny smashes Larry's head in with a salt lick.
This one may be debatable, considering that there's no way to know if Larry is truly dead or if he could be resuscitated. If it was the former, he would come back as a walker which, considering that the group is in an enclosed space with no weapons, was something Kenny was trying to avoid.
In Episode 5, No Time Left, Lee talks to a man (dubbed simply "The Stranger") whom you and your group accidentally screwed over, and who was going after you for revenge. While you can sympathize with him, he admits that if Clementine, who he, for all and intents and purposes, kidnapped, were to go with Lee again, he would kill her himself. And depending on how you interpret him, he's probably not even doing this for Clementine's sake no matter how much he says he is, he's just trying to find someone else to blame for his own mistakes.
In the third episode of Season Two, Carver spends pretty much the entire episode pole vaulting right the fuck over the horizon.
World of Warcraft/Warcraft III: The first time Arthas Menethil does this can be summed up in a single short sentence. Six little words: "This entire city must be purged." Even if you accept the argument that it was necessary (the city could potentially be infected, anyone that Arthas didn't kill would be killed and reanimated as a Dreadlord's undead slaves anyway, and it's impossible to cure the Plague of Undeath — and Arthas, canonically, knew the first two facts at the very least), the fact it was his first option, and he angrily turned on the Knights of the Silver Hand for refusing to participate, points out that he was on very, very shaky moral ground.
Unfortunately, while the massacre is this from a lore viewpoint, gameplay-wise it is entirely possible to complete the Culling mission without harming a single living/uninfected person. (All villagers become zombies a few seconds after their homes are destroyed. In fact, if one is trying to manage multiple areas, it is arguably easier to wait for them to turn, as the peasants are neutral and require direct orders to attack while the zombies will be automatically engaged by your troops.)
A straight up example is when Arthas willingly sacrifices Muradin to acquire Frostmourne. Muradin does survive somehow, but still.
And even then, it's debatable. Cairne Bloodhoof, prior to his death, overtly questions if Hellscream's sacrifice was enough to redeem him after all the atrocities he committed. Part of this potential white-washing might be a result of then-Warchief Thrall, who was generally well-loved by the orcs, being a Hero-Worshipper and former close friend of Grom's who was willing to overlook his mistakes on a personal level.
Neltharion, later known as Deathwing, crosses the Moral Event Horizon when he tricks the other Dragon Aspects into giving much of their power to the Dragon Soul, and then turns on them and kills nearly all the blue dragonflight. The rest of the Black Dragonflight crosses it with him in the eyes of the Red Dragonflight in World of Warcraft: Cataclysm, and the player is tasked with eliminating them in the Twilight Highlands. There was also the matter of him causing a massive earthquake that does enormous damage to Azeroth...
Malygos crosses the Moral Event Horizon when the player, after defeating one of his minions, finds a letter that reveals that he forced them to work for him under the threat of their family being killed. Like Deathwing, when Alexstraza learns of his plans, she sadly decides that he is beyond redemption, and decides to kill him to save Azeroth.
Garrosh Hellscream has always been controversial, but a lot of people doubt he will have many sympathizers left after the destruction of Theramore, leading to the deaths of hundreds, including Rhonin!
More recent acts include trying to assassinate Vol'jin, attempted enslavement of the Darkspear Trolls, deliberately infesting his men with Sha, and trying to kill Anduin Wryyn.
Garrosh has in fact passed the MEH in-universe with a growing faction of the Horde (led by Vol'jin) starting a revolution to overthrow him. The act that kicks off the final push to overthrow him is him unearthing the heart of the Old God Y'Shaarj and putting it into the lifegiving Pools of Power. As a result, the sacred Vale of Eternal Blossoms is destroyed, the defenders are killed and/or sentenced to eternal torment reliving their failure, and Garrosh now has a weaponized Old God at his disposal that he intends to use to conquer the world — you can see a vision of Stormwind destroyed and all his enemies impaled on spikes.
Overlord Krom'gar crosses this at the end of the Stonetalon Mountains storyline for the Horde, detonating a bomb that destroys a school for training druids. High Chieftain Cliffwalker makes a reference to this, and even Garrosh, who at this point had not yet crossed his own Moral Event Horizon but was still a questionably violent warchief, believes Krom'gar had gone too far, and punishes him by death.
High Chieftain Cliffwalker: "You are about to cross a terrible threshold, Krom'gar. May the Earth Mother have mercy on your soul."
The Alliance is not without a war criminal or two. Sky Admiral Rogers, near the start of the Jade Forest storyline, has Horde troops gunned down while they try to swim to safety. This disgusts Rell Nightwind, a night elf SI:7 operative, so much that he begins to question the cause, and spawns sha that are manifestations of his doubt.
Though it's hardly surprising given her Freudian Excuse. When the player mentions that she seems to have it out for the Horde, she replies that she was born and raised in Southshore (which was recently plagued by the Forsaken).
Also of note is Admiral Daelin Proudmoore, who pushed the major factions back to the brink of war because he and his didn't get the memo that the Horde was trying to mend its ways. A great deal of blood was spilled because the Admiral found it impossible to believe that the extra-planar invaders had suddenly decided to reform. Though as with most Alliance "villains", it's debatable whether they cross a moral event horizon or had simply fought one too many demon-worshipping hell-orcs to see them as anything but mass-murdering monsters.
Interestingly enough, events in Mists of Pandaria have lead to Daelin getting a case of Vindicated by History when Garrosh destroys Theramore. Jaina overtly comes to believe her father was right and that she should have never trusted the orcs. Though she sort of calmed down when Kalec and Thrall bluntly tell her that she is literally acting just like Garrosh.
And as of patch 5.1, some people have claimed she's finally gone over the edge with the Purge of Dalaran, where she discovers Blood Elf spies working for Garrosh have been using the city's portal system to smuggle supplies for the Horde war effort. Rather than just trying the criminals, she orders all of the Sunreavers to surrender themselves for imprisonment, and orders Veressa to execute anyone who resists. Opinion is mixed as to whether it was a severe overreaction and blaming people who didn't deserve it, or if it was justified and long-overdue karma for everything the blood elves have done to the Alliance since they left them.
She definitively crosses it after Garrosh's defeat. During the Horde's deliberations on selecting a new Warchief, Jaina encourages Varian to have all of the present Horde leaders killed in order to preemptively defeat them, Thrall included.
The novel "War Crimes" implies that she has pulled back from it, being temporarily insane post Theramore. She even outright states that Garrosh should NOT be used to represent orcs in general since they have tried to amend for their misdeeds.
Lieutenant Virgil from Xenosaga was a Jerkass from the start, but he crosses the Moral Event Horizon when he blows up some Realians for no better reason than that there's some chance it might buy some time, and talks cheerfully about how he loves eating their flesh. When he dies shortly thereafter, Shion still cares, but the player most likely doesn't.
In the third game, his abject hatred of Realians and his cannibalistic tendencies are made a bit more forgivable when you learn about his backstory with Febronia. His final scene in particular almost tips him into Jerkass Woobie territory... for some, anyway.
His cannibalism due to DME addiction may be a side effect of Febronia donating her organs to him.
Albedo. He kidnaps MOMO, proceeds to subject her to some horror involving self-mutilation and regeneration, then mind-rapes her to get the Y data. While doing so, he plants some kind of mind-bomb in her so that when the heroes try to get the Y data later, it more or less makes her mind asplode. And despite all this, he's still one of the most popular characters.
The space combat simulator X-Wing Alliance had a richer plot and cast of characters than its predecessors, particularly a subplot involving the protagonist Ace Azzameen's family. When Ace is new to piloting for his father Tomaas' shipping company, he helps out with a covert delivery of bacta to the wounded soldiers from Hoth, only for the Empire to show up and destroy the freighter that Ace's father and eldest brother were on. Their uncle Anton helps them escape to the Rebel Alliance. Near the end of the game, Anton gives them information that indicates that Tomaas and Galin are alive on an Imperial prison station. When the Azzameen children go to rescue them, Imperial ships arrive to capture them. They learn that their dear Uncle Anton not only set them up, but told the Empire about Tomaas' bacta run way back when. To recap, the man sold his own brother and niece and nephews out to the Empire, all because he figured Tomaas' dealings with rebels would ruin their business.
Final Fantasy Tactics has the despised Algus Sadalfus, who at first appears to merely be a classist Jerkass until he casually kills Tetra when an enemy tried to use her as a Human Shield.