"Moral Event Horizon", or "MEH" for short, refers to an action by a villain that is so evil that it usually eliminates audience sympathy for the villain and makes it clear that they are unrepentantly evil and will not be redeemed, unless if they themselves are offended by the actions of another villain, or admit themselves that they are beyond redemption.
The scientific fact that nothing can escape a black hole is referred to as the boundary of the region from which no escape is possible and is known as the event horizon, hence the term Moral Event Horizon. A villain who crosses the horizon, or enters the black hole, has no hope of escaping except under extremely rare, extraordinary circumstances.
All Complete Monsters are by definition beyond the Moral Event Horizon. However, crossing the Moral Event Horizon does not necessarily make a villain a true Complete Monster, it only means that they are irredeemably evil. Some villains have or almost crossed the Moral Event Horizon, or done something despicable enough to make the fans believe they did so, only to later redeem completely or partially. A strong example of a Complete Monster would be either a villain who (in addition to having no adequate Freudian Excuse) commits multiple especially heinous Moral Event Horizon-worthy deeds, or a villain who is exceptionally brutal and evil in nature when crossing the MEH.
However, some villains of this who crossed MEH would die in disgrace and become Damned Souls.
By definition, a character can only cross the Moral Event Horizon once; however, it is possible for a villain to have more than one event as a potential Moral Event Horizon, such as the various adaptations of the Joker and Teridax. Other villains have more than a potential and often leave an impact on the public that they do wicked things all the time and commit Moral Event Horizon acts like a hobby, such as Zalgo, Pepper Satanica, Gan, and Ernie the Giant Chicken. These characters are almost invariably Complete Monsters.
IMPORTANT NOTE: Two things that should not added on the list of MEH below: Fanon examples, as this would confuse the reader. Certain flawed actions that done by characters that confirmed not evil nor antagonistic (Franny Robinson grounded her son Wilbur until his death for his mess that also led Lewis present in the future or SpongeBob's ungrateful acts on Gary in spite of his heroic acts for saving him from Puffy Fluffy for examples) won't be ever counted as act of MEH if the said actions not officially put them to the dark side or merely portrayed them as flawed hero.
- Gan: Crosses it when he kills his own brother, Aslan.
- He crosses it again later on when he enslaves the entire Macroverse, devouring many innocent planets and enslaving way over a trillion people.
- Jack Savage: He crosses it when he blows up the US Capitol and all inside simply to make Maturin look bad to the public.
- He crosses it again when he gasses Judy Hopps with a gaseous form of Night Howlers and forces her to attack Nick Wilde.
- Jeff (Pasta Monsters): Blows up a children's hospital.
- BEN (Pasta Monsters): He crosses it in "The 120 Days of Soda", where he kidnaps, and starves children in his weed factory, forcing them to make weed for his small company.
- Zalgo (Pasta Monsters): Although he crosses it more than a few times, he first crosses it when he rape his first queen and takes over the Dark World, torturing it's inhabitants for years.
- Mancala: Kills Laughing Jack and tries to kill Jeff's five year old daughter, Sally.
- Enderman (Pasta Monsters): Crosses it when he turns into a demonic dragon, destroys a sacred forest, turns it's inhabitants into mindless slaves and tries to kill Jeff and his friends in "The Chain Mail"
Margra Batto And Kyra Verbeten
- Pepper Satanica: Severely crossed it when she ruthlessly killed her twin sister, Kiota Angelica.
- She Crossed it again when she Destroyed Spyro Doomfire's Home Planet.
- She crossed it the third time when she stole Kiota's cross Necklace and turned it into a black diamond.
The Last Jedi
- Ernie the Giant Chicken (The Last Jedi): Ernie, being evil personified, is easily one of the most depraved villains in the entire story. There is a strong debate to mention what is the most absolutely monstrous thing Ernie has ever done. The list of examples are down below.
- In his time before being emperor, he was defeated via imprisonment in a black, tree-like crystal. However, he still was able to commit evil acts within the prison using the protruding spikes the crystals could create. He was responsible for elminating all the beautiful, mythical creatures that ever existed in the Crystal Empire, causing them nightmarish agony while the oil created by the crystals destroyed their food, homes, and devoured them alive. Later he continues the random killing (including more homes and innocent ponies). When the return of Ernie occurs, he becomes even worse: he forces the then Jedi Knight, Peter Griffin, to watch helplessly as he began destroying the Crystal Empire and the slaughtering of the Crystal Ponies with a sadistic glee.
- When Ernie makes his return to power, he manipulates the genuinely good Jedi, Chris Griffin, into leading the mass extinciton of the Jedi Order. As emperor, Ernie destroys Chris' home planet, the Jedi Temple, and many other beautiful forests and planets, all while laughing maniacally. He also kidnapped Chris' girlfriend, Sunset Shimmer, and forced Chris to kill her. He also made Princess Celestia, Princess Luna, Princess Twilight Sparkle, and Chris' family die as old slaves deprived of adequate food and water. He also imprisoned Chris' closest friends and enslaved them for years (and perhaps decades) and sentenced them to forced labor while depriving them as well as all Jedi of health, food and water. Something which he would repeat for over trillions of people and lands for thousand of years. Worse, the slaves of his goverment are punished terribly and sometimes executed, impaled or crucified, such in the case of the Wookies. And as if that was not enough, he also plundered the resources of trillions of other planets. Ernie also caused galactic-level space wars as a hobby, and had many races slaughtered to secure his power, or simply because their pain and agony amuses him.
- Another easy crossing for Ernie was in "Chris and The Fire Demon". Ernie had attacked and decimated the land of a respected Jedi master. Even as the villain decimated all his fellow Jedi and loyal subjects, the man fought against Ernie. As punishment, Ernie encased the man in an unbreakable field of Force Lightning and forced him to watch as he slaughtered everyone he loved and destroyed his kingdom, finally placing him within the depths of a mountain, refusing to grant him a warrior's death.
- Blackmail is a routinary occurrence for him, as well as one of his most despicable actions. Good examples of this are episodes "XLIV" and "L". Similarly, both episodes ends up with disturbing implications.
- Atrocities are a daily occurrence since Ernie's rule, as he welcomes wanted gangsters, bounty hunters, and intergalactic criminals from across the galaxy and provides them with planets that are still fully occupied, entrusting the new arrivals to wipe the populaces from the galaxy. Even scarier is knowing that this is a routine occurrence under under Ernie's rule.
- In "Seeing the Light", an entire village of alien children are kidnapped and forced into a violent frenzy against everything around them. However, it's never specifically stated that this was on Ernie's orders. The episode largely deals with coming to terms with Ernie's effects on the universe. It is also shown the slaver of the children was one of Ernie's personal Royal Guards, so it's a safe bet that he is affiliated with the heinous act.
- In "Seeing The Light", he also nonchalantly kills Joe Swanson along with an entire army of rebels. Arguably worse is that Ernie had intended to slaughter all of Joe's daughters, and would have had their father not distracted him.
- In Season 5, one of his most monstrous acts was when he dragged Chris out of the last time portal and destroyed it, taunted him while he was in a violent rage, and turned the innocent little Ewoks that led him to the portal into monsters so Chris could to have something to kill.
- In the penultimate episode, he forces his daughter, Lara, to fight Chris and eventually corrupts her body, putting her in a state where she is aware of her actions in her corrupted form. And to make this worse, he had just met her and is quickly made aware of Chris' and her feelings for each other.
- In the final episode, Ernie crosses the line once again by forcing his possessed daughter, Lara, to kill Chris. When the rebels arrive to help Chris, Ernie tells his men that whoever kills Fluttershy will get their own planet, knowing how much Fluttershy means to Chris. Ernie tortures Lara to near-death with Force Lightning, and is highly amused when Chris gets in the way of the blasts to save Lara. When Ernie hears that Lara has been "adopted" as a surrogate daughter by Chris' allies, he promises to kill them too, and orders Sideshow Bob to kill the Cutie Mark Crusaders (who are all children). When Chris arrives for the final battle, Ernie states that after he kills him, he will destroy every planet Chris has committed good acts in so no one will be able to spread tales of his heroics. And finally, Ernie manages to kill Quagmire before finally being ended by Chris'.
- Sideshow Bob (The Last Jedi): Sideshow Bob is perhaps the most vile villain in the entire series, sans Ernie. Much like Ernie, Sideshow Bob has many potential crossings
- He assisted Ernie in causing the extinction of the Jedi, personally killing any Jedi in sight, including a youngling who was attempting to defend the Equestrian Princesses.
- During Ernie's rule, Sideshow Bob made a nasty habit of torturing and murdering trillions of innocents across the galaxy. He was responsible for sending entire races to a life of slavery and made a habit of destroying their homes and villages, typically along with the inhabitants. He also ordered many planets to be destroyed to ensure no rebellions would rise.
- In "100 Years Have Past", an entire village of people are massacred by Clone Equines. Afterwards, the Clone Equines attempt to murder a little girl, her mother, and her newborn baby before they are rescued by Chris. Seeing as the Clone Equines are led by Sideshow Bob on the field, it's a safe bet that Bob is affiliated with the heinous act.
- Sideshow Bob later crosses it yet again when he and his squad casually massacre an entire village (consisting of innocent men, women and children) just to draw out Chris. This becomes even worse when it's later revealed Sideshow Bob regularly commits similar evil acts, mostly for pleasure.
- Darth Griffin: Crosses it when he killed the Jedi younglings.
- The Cult Leader: She crosses it when she brutally tortures her daughters from childhood, turning them into sentient weapons.
- Imperial Royal Guard (The Last Jedi): He crosses it when he slaughtered a village, kidnapped its children so that he could, well, use them as child soldiers for the Chicken Empire. When Chris and Lara came to their rescue, he uses mind control to make them attack Chris, knowing he'd be unwilling to fight innocent people against their will. And then he tried to torture and kill Lara with several thousand volts of electricity.