Due to the moral greyness of the series, many characters avoid this trope in spite of performing some pretty terrible deeds, but there are still a few irredeemable bastards.
- Viserys Targaryen putting a sword to his pregnant sister's belly and threatening to cut her unborn child out of her, in front of the child's father no less. And he only does this because he's throwing a tantrum over not getting his way right now and because he's jealous of his sister's happiness. No coming back from that. Notably, Daenerys has put up with Viserys' abuse for years, forgiving him and making excuses for him, but at this point, even she feels he's finally gone too far.
- Joffrey Baratheon crossed it when he has Ned Stark executed, especially since he first made it look like he was going to do the exact opposite. This leads to the North rising up against the Iron Throne and seceding from the realm. When confronted about his promise to be merciful, he coldly replies that giving Ned such a quick and clean death was a mercy. His actions after are a long series of kicking dogs whenever there isn't someone else to rein him in.
- Craster crossed it years ago when he decided to further his family line by raping his daughters, who would give birth to more daughters for him to have as extra wives. And his sons were basically sentenced to death by being handed off to the White Walkers.
- If Janos Slynt's betrayal of Ned didn't put him over the edge (he was only doing what he was paid for, after all), then leading a massacre of Robert's bastards, including personally killing a baby in front of her pleading mother certainly did.
- Petyr "Littlefinger" Baelish threatens Ros by revealing that he serves up disobedient and nonperforming prostitutes to thrill-killers who torture them to death. From this point, it's clear that Littlefinger isn't just another schemer; he's evil to the core. As the show progresses, it turns out that this is only one horrible crime of many up his sleeve.
- Polliver killing Lommy Greenhands by stabbing him in the throat. It certainly doesn't help that he's also revealed to be a serial child molester, even by the lax standards of Westeros.
- Dagmer killing the elderly and defenceless Maester Luwin entirely for the hell of it.
- Kraznys mo Nakloz, the slave master of Astapor, crossed it long ago when he made each Unsullied kill a newborn baby in front of its mother at the end of their training. He makes a point of stating that the masters of the enslaved women are paid compensation with no thought given to the grieving mothers at all.
- Locke confirms what sort of person he is pretty quickly when he prepares to rape Brienne (only stopping because Jaime bullshits him about her value as a hostage) and then cutting off the chained and helpless Jaime's sword hand, even after he'd made his point quite effectively, apparently just because he resented Jaime's aristocratic overconfidence in his own authority and the reputation of his father, and enjoyed the role reversal.
- Rast crosses it the moment he stabs Lord Commander Mormont in the back. The fact Mormont fought till his very last breath and then Rast the asshole stabs him over and over again when he's down demonstrates what a low-down coward he really is.
- Any sympathy that could be had for Rickard Karstark is immediately shitcanned when he murders two young, innocent squires in cold blood simply for bearing the Lannister name.
- The Red Wedding is one long crossing for Roose Bolton and Walder Frey. Walder had Robb Stark and all of his bannermen massacred just because he didn't marry Walder's daughter, and Roose turned on his fellow Northmen and personally killed his own king. It's also emphasized multiple times that in doing so, Walder killed guests beneath his roof, which is considered one of the worst crimes of all. One could argue that Tywin Lannister's organising the whole thing might itself make him applicable for this, though he at least has pragmatism as an excuse.
- Balon Greyjoy chooses to abandon his own son after he receives his genitals and a ransom demand, saying that "he isn't a man anymore," despite Theon's entire predicament being due to a desperate wish to win love and acceptance from his father. Even scumbags like Walder Frey treat their kids better than this guy. His refusal to save Theon and his snide little insults at his lack of manhood angers Yara so much that she calls him out on his behavior and begins preparations for a rescue mission.
- Gregor Clegane, already established as a reprehensible piece of work, crosses it even before his first appearance, when he murdered Elia Martel's children in front of her, then raped her and then bisected her. Granted, the first of these was an order by his liege Lord, but the way he did it and his actions afterwards is inexcusable.
- The overlords of Meereen fly far over the Moral Event Horizon before they even appear by crucifying over 163 slave children to mile-posts on the way to Meereen, just to piss Dany off. This is made worse as the first girl sacrificed visibly resembles Dany herself, making this slight at her seem even more intentional.
- Karl Tanner crosses it when he takes over Craster's Keep. He rapes and brutalizes Craster's daughters, drinks wine from a cup made out of the skull of Commander Mormont, and is willing to murder a baby just so he won't have one more mouth to feed.
- Tywin Lannister definitely crosses it before Tyrion snaps from his abuse and murders him:
- First contender: he is Gregor Clegane's boss, so the fact that he is ultimately responsible for much of the Mountain's atrocities could qualify. However, some may feel that may be too much of Off Screen Villainy to qualify.
- Second contender: he is the true mastermind behind the Red Wedding. Then again, some might argue that he was simply being ruthlessly pragmatic.
- If neither the first nor second allowed him to cross the line, then he definitely crosses it with the third: letting Tyrion take the fall for Joffrey's murder without caring the slightest bit if he's innocent and if he is executed as a result. It's very fitting that he dies shortly afterwards.
- The Sparrows at first seem like some of the most good people in the show, wanting to help out the common people in whatever way they can and prepared to sacrifice anything of their own to do it. Then they get the power of the Faith Militant and it turns out they're far more Westboro Baptist Church than Christian missionaries.
- Thought Meryn Trant wasn't bad enough already? The last two episodes of Season 5 say otherwise. Being a pedophile is horrible enough, but the sick bastard legitimately gets off from beating prepubescent girls with a switch. Thank goodness Arya saved them before his abuse went too far, and gave Trant the utterly satisfying death he deserved.
- Both Melisandre and Stannis Baratheon finally cross the point of no return and become true villains when they have Shireen burned alive in an attempt to ensure their victory over House Bolton. Numerous viewers, including long-time fans of Stannis, have turned on him for this act, and some are going so far as to root for the Boltons over him.
- Myranda loses all sympathy when she mockingly tells Sansa that she plans to dismember her body to make her life under Ramsay Bolton a Fate Worse than Death. Some would argue she'd already crossed it long before though, as she actively participates in Ramsay's numerous rapes, tortures, and murders, and appears to actively enjoy it as much as him. She actually persuaded Ramsay to kill one of his girlfriends because she was jealous of her and mockingly stated she wasn't "so pretty now" during her death.
- Wanting to kill the innocent Myrcella in revenge for Oberyn's demise is appallingly bad on its own, but going through with it after Prince Doran mercifully grants Ellaria and the Sand Snakes a second chance puts all of those women way past redemption. And they only go further in the Season 6 premiere when they kill Doran and Trystane as well, all in the name of "avenging" Oberyn. That act is even considered to be kinslaying, which is one of the worst crimes in Westeros. So cruel and repulsive are their actions, that when Ellaria and Tyene are at Cersei's mercy in "The Queen's Justice", fans were rooting for Cersei.
- The Night's Watch brothers who are involved in the betrayal of Jon Snow. Particularly Olly, whom Jon was kind enough to take under his wing.
- Ramsay Bolton may be a monster who enjoys physically, psychologically, and sexually tormenting people and commits atrocities as casually as most people eat breakfast, but the moment he lost his last shred of humanity was when he killed his father, Roose Bolton. Regardless of the fact that Roose was a pretty horrible person himself, he was the only one who ever brought out Ramsay's vulnerable side. Ramsay always dropped the smirk and "playful" voice with his father, and the day Roose announced that Ramsay was legitimized was the happiest moment of the younger Bolton's life. When Roose threatened to disinherit Ramsay after Sansa escaped from him, Ramsay responded by murdering his father to cement his position as Lord of House Bolton, killing the one person in the world he ever loved. And shortly after, he feeds his baby brother to his dogs, also to maintain his power.
- Smalljon Umber crosses it by callously watching on as his proper liege Rickon Stark is murdered by Ramsay after delivering Rickon to him.
- It was thought by many that the Brotherhood Without Banners crossed it in Season 6 when they slaughtered peaceful followers of the Seven who wouldn't pay their protection racket - although, as it turns out, these men are not representative of the whole Brotherhood, and their decision to go rogue is promptly dealt with by Beric and Thoros in the next episode.
- The Waif of The Faceless Men was merely a thoroughly unlikable Sadist Teacher towards Arya during her hellish training there. But murdering Arya's pregnant caregiver Lady Crane in cold blood to spite her before attempting to take her life is when she crosses the line for good.
- Cersei Lannister had made a lot of evil choices over the course of the show, but she solidifies herself as irredeemable in the Season 6 finale with the Green Trial, where she commits mass murder. Cersei blows up the Sept of Baelor with wildfire and not only kills all the Sparrows, but also her uncle, cousin, the entire Tyrell family save for Olenna, and dozens of innocent people.
- Even the apparent Pet the Dog moment when she tries to spare Tommen backfires. Her actions cause him to commit suicide, and, as if to hammer the point home, after six seasons with her love for her children being her most redeeming quality, Cersei coldly brushes off her remaining child's death.
- If that act isn't enough, just before Tommen's suicide, she tortures Septa Unella by first waterboarding her with wine, then leaving Gregor Clegane, a psychopathic serial rapist who himself is well across the Horizon, to do whatever to her.
- And to top it off, Cersei refuses to aid Jon and Dany who gave her proof that the Zombie Apocalypse is real and decides to let the White Walkers finish them off. She doesn't care about humanity's survival and that these two have the best weapons and knowledge against the undead. All she cares about is herself even though Winter approaches on King's Landing. She's also willing to kill her own brother/lover on the spot when he leaves her (though she doesn't actually go through with it), and after he leaves her, she orders his and Tyrion's deaths if they survive the war against the Night King.
- And just to remind people how terrible she is in Season 8, not only does she bring all the civilians in to surround the Red Keep and use them as a human shield essentially, she orders Ser Gregor to behead Missandei after making it seem like she'd consider Tyrion's offer to let her and her unborn child go if she agrees to surrender. At that point, she's almost as bad as her firstborn son.
- The penultimate episode of the series gives us a major one. Having fully crossed the Despair Event Horizon after the death of her second dragon, the execution of her oldest remaining friend, betrayals from within her inner circle, and reaching a political and emotional impasse with the man she loves, Daenerys goes on a rampage and needlessly incinerates countless innocent men, women, and children throughout the streets of King's Landing. The carnage and horror the people suffer at both Dany's own hand and the cruelty of her rampaging soldiers is given great emphasis.
- Also from the penultimate episode, after losing the woman he loved, Grey Worm crosses this when instead of keeping his soldiers in check, he follows his master's example and backstabs soldiers who had already surrendered. By doing so, he sends the invading army into a crazed frenzy that rapes, burns, and kills its way across King's Landing. He's indirectly responsible for who knows how many people suffering and dying because he couldn't hold his temper in check.
