With over a decade of Marvel movies behind us, there are a lot of good, and not so good, movie moments to reflect on. The MCU has brought our favorite comic book characters to life on the big screen, and popularized the characters more than ever before. The Marvel movies, though they do stray from the original source material and mix different comic book stories together, don't make up their plots out of thin air. Unfortunately, the comics do not all fit the upbeat, family-friendly vibe of the MCU and especially now that Disney owns Marvel, there are some dark corners of the Marvel Universe that will never make it to the theaters.

Kids and adults idolize these Marvel heroes, and the veil would be shattered if fans of the MCU knew about some of the more disturbing comic book plots that the Avengers have encountered. From taboo acts to illegal substances and terrifying murders, the Marvel crew is much more dangerous and dark than the MCU lets on. Some of these plot points are so bad they were ret-conned from comics completely. If that isn't a big red warning flag not to make a movie about it, we don't know what is.

15 THE HULK WAGES WAR

World War Hulk

We just saw the kind of large-scale damage that one rogue Hulk can do in Thor: Ragnarok. In "World War Hulk", Hulk is sent to space, where he conquers a planet and has a wife and son. When his wife and son are killed, Hulk seeks revenge on everyone who has ever hurt him. He mangles Black Bolt for trying to stop him, and sets his sights on destroying all of New York City. Even a Hulkbuster Iron Man, an ax-handed Doctor Strange, and all of the Fantastic Four can't stop him.

The Hulk sets his friends up in a death arena and makes them fight each other, but he is finally arrested and trapped in a coma, in a prison beneath the Earth's crust. The Hulk might be violent, but seeing him try to murder all his friends would not make for a happy movie.

14 TONY STARK'S KILLING SPREE

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Iron Man has made some mistake in the MCU (like accidentally creating Ultron...oops) but he is still a hero, and still a valued member of the team. We know Tony can be selfish and hot-headed, but the at least the MCU Iron Man is not a murderer and a traitor. In the '90s, "The Crossing" storyline revealed that Tony Stark had been a sleeper agent the entire time, and when he was found out, Tony went on a murderous rampage.

He brutally kills the female Yellowjacket, the nanny of Quicksilver's daughter, and Amanda Chaney, before he was taken down by a time-traveling teenage version of himself. Luckily, this whole thing gets erased by a later storyline, but evil, murderous Iron man is not a plot point that is fit for the MCU. If comics decided it was too bad, it probably doesn't belong in the movies.

13 QUICKSILVER AND SCARLET WITCH GET TOO CLOSE

quicksilver-scarlet-witch-incest-relationship

When a character dying in the movies is the best possible scenario based on their comic book history, you know that something deeply dark and wrong is going on behind closed doors. In the MCU, Scarlet Witch and Quicksilver are close siblings, but not quite as close as they were in some of the comics, which is certainly a good thing for the family-friendly Marvel movies.

In The Ultimates, a futuristic, alternate universe version of the Avengers, Quicksilver and Scarlet Witch are still twin siblings. Unfortunately for fans, they are just as close in adulthood as they were in the womb, and if we pay attention to the subtext, they get a little too close for comfort. Whatever happens to Scarlet Witch and Vision in the MCU, dating a sentient Infinity Stone is infinitely better than putting this relationship on the big screen.

12 THE SINS OF THE PAST

Spider-Man and Sarah Stacy from Marvel Comics

Spider-Man gets into plenty of trouble on his own, but sometimes the terrible things that happen to him are really out of his control. In "Sins Past", some of the darkest moments in Spider-Man's life make for a disturbing story that should never make it into the MCU. Spider-Man loved Gwen Stacy, and Gwen loved Spidey...but she loved someone else, too, and the consequences of her mysterious secret were disturbing. In the worst fanfic ship come to life ever, Gwen hooked up with the Green Goblin, Norman Osborn. Even worse, she ended up with twins.

The twins had some mysterious comic book disease that hyper-aged them to adulthood, when they came after Peter Parker with a vengeance. There is not much to the twins as villains, but no one needs to see Gwen and the Green Goblin get it on in the MCU.

11 HYDRA CAP

This is one of the most recent and the absolute worst things to ever happen to Captain America. Captain America is the stalwart, All-American, justice-seeking head of the Avengers. He is the ultimate hero, and is always around to do the right thing. That is why, when he was revealed to have been a Hydra agent the entire time in Nick Spencer's extremely controversial comic storyline, fans were outraged and disgusted.

Of course, Hydra Cap was not really the true Captain America, but the imagery and betrayal involved in revealing Captain America to be an Agent of Hydra and a complete traitor is a plot point that does not belong in the MCU. Fans of the Marvel movies, especially kids, know Cap as the all-around good guy. If he suddenly turned out to be evil, fans of the family-friendly MCU would be devastated.

10 HULK SMASH DAD

Bruce Banner has been framed in the MCU as a nerdy, quiet scientist trying to quell the beast inside of him. Sometimes the Avengers need the Hulk, though, and one smash can save the day. Before he was even the Hulk, Banner had some violent tendencies that he tried to hide, and fans try to ignore. It could be framed as heroism, but that doesn't mean it isn't murder.

When Bruce is grieving the loss of his mother, he seeks revenge on their abuser, his father, Brian Banner. Though for many years Bruce convinces himself it was an accident, it's hard to accidentally murder tour father by smashing his skull into your mother's headstone. This dark side of Banner is too much for the watered-down Hulk of the MCU.

9 JUST ONE MORE DAY

Spider-Man's heroics started when he was avenging the murder of his Uncle Ben, but he was left with his Aunt May to take care of him. Then, he found Mary Jane, got married and started a family. For once, everything was going right for Peter Parker. That is, until Aunt May was shot, too. He made a deal with the devil, Mephisto, and got Aunt May back, but at a great cost.

He chose to reverse his marriage to the pregnant Mary Jane. While this was essentially a four-part series set on retconning the happiest time in Peter Parker's life, it was also one of the darkest, most depressing timelines in all of Spidey's history. The joking, fun Spidey we see in the MCU would not be able to carry this kind of story.

8 THE ULTIMATE ULTIMATUM

Ultimatum Wolverine is Oliberated by Magneto

Ultimatum is a short series of comics that brings sadness into the hearts of Marvel fans everywhere. It's clear that this story line should never, ever, be a movie. The focus is on Magneto, who is trying to avenge the death of his kids (one of whom is still alive but that doesn't make a difference). He snaps Professor X's neck in a gruesome scene, and that is not the end of the over the top violence.

Most characters die, including Daredevil, Doctor Strange, Cyclops, Emma Frost, Thor, Hank Pym, and many more. Wolverine had the Adamantium violently ripped from his bones. The most gruesome scene, though, is when the Blob kills and cannibalizes Wasp. This movie would be way beyond an R rating, and shouldn't be a part of the MCU.

7 TONY'S DEMONS

tony-stark-demon-in-a-bottle

Tony Stark is known for being a genius playboy philanthropist, but that is treated as more of a joke in the MCU than an actual description of his personality. He is still a hero, and an important member of the Avengers. Later in the franchise, it is revealed that he and Pepper Potts are on the rocks, but the movies skip some darker moments in Tony's life.

The MCU paints Tony as a well-meaning genius who gets a little headstrong and self-centered, but the comics tell a much more disturbing story. In "Demon in a Bottle", specifically, fans got a dark glimpse into the severe alcoholism and addiction that ruined Tony's life. The arc ends with a hopeful Tony seeking help from his friends, but this dark time in Iron Man's life has no place in the MCU.

6 CAPTAIN AMERICA'S ADDICTION

captain america meth

As we have seen in joking PSA commercials in the Marvel movies, Captain America is the poster-child for good behavior. He stops his friends from cursing, always treats people with respect, and never forgets to say "thank you". Sometimes Captain America slips up, though, and those dark moments are something fans should never have to live through seeing on the big screen.

In one storyline fans wish they could forget, Captain America gets high on meth. In a misguided one-man battle in the war on drugs, Captain America decides to blow up a Meth lab, but of course it is super-meth (thanks comics) that affects his Super Soldier blood. Cap goes on an insane rampage and gets himself into some really weird trouble. This might be a story about how drugs are bad, but it's definitely too weird and dark for the MCU.

5 HANK PYM'S BAD SIDE

Ant-Man Hits Wasp

For comic fans who saw Ant Man, there was a collective sigh of relief when it was not a historical account of Hank Pym. Hank was a genius, and he created Ant-Man, but he was also an angry man with a serious problem. In one crushing comic panel that will go down in history forever, Hank hits his wife in a fit of rage. The Ant-Man movie focuses on Pym as an older character who is distant, but not outright abusive.

The movie focuses more on the new Ant-Man, and the movie is a heist comedy. With this set up, and the overall tone of the MCU, a scene of disturbing spousal abuse would never fit in. Some fans insist that Pym was not abusive, and just gets a bad rap, but hitting someone you love is never acceptable, and it's not a message that belongs in the MCU.

4 SPIDER-MAN'S PROBLEMATIC FLUID

Spider-Man's radioactive fluids are dangerous Reign 03-11

How can you give someone cancer? It's not like cancer is contagious. Spider-Man never even had cancer to begin with, how could he give it to someone else? Well, the answer to this question leads to one of the most disturbing and strange stories to ever defile the pages of Marvel comics. Spider-Man does not have cancer, but he is radioactive, as a result of the spider bite that caused his mutations and powers.

Unfortunately for Mary Jane, his blood, and... other fluids, are also radioactive, and she came in contact with them. A lot. She reveals it in a roundabout way, but there is no question that Mary Jane got her cancer from repeated exposure to some very intimate radiation. For our happy go lucky MCU Spider-Man, hopefully this is a dark secret he never has to encounter in the MCU high school health class.

3 VISION BUILDS A FAMILY

In a recent standalone Vision comic book series written by Tom King, The Vision, we get a glimpse of what life would be like if Viz didn't hang out with the Avengers all the time. When he is basically forced out of being a hero, Vision retires into a boring government job, just like a regular guy. He also, like a regular guy, wants to settle down and start a family.

Unfortunately, as a super-powered android, that is not a simple task. Vision secretly assembles a wife and two children, and moves them into a suburban house. They go to school, go to work, and try to get along with the neighbors. Unfortunately for Vision, they also murder. In the MCU, building murderous androids is frowned upon (remember when Tony accidentally created Ultron?), so the likelihood of Vision's dark family secrets making it into the MCU is thankfully very low.

2 THOR MEETS THE VIKINGS

Usually in the MCU, Thor is portrayed as a joking Asgardian who doesn't understand puny human customs and likes to throw his hammer around. In comics, that is not always true. When Thor encounters a horde of Vikings, it turns into one of the most bloody and terrifying Thor stories of all time. Thousand year old Zombie Vikings are not regular comic book villains. They are only bent on defiling and destroying all the towns they meet, and all the people who live there.

When they converge on new York, Thor tries to stop them, but they break both of his arms, tie Mjolnir to him, and toss him into the Hudson River. Everything ends up going back to normal, but Thor is mangled and many of the other Avengers are beaten, too. This is one Thor story that shouldn't show up in the MCU.

1 THE DEATH OF CAPTAIN AMERICA

Captain America Death Marvel Comics

Since his premiere as the twiggy teenager who would become a Super Soldier, the world has been absolutely smitten with Chris Evans. He is the quintessential Captain America, an all-American kid with a big heart and a thirst for justice. He leads the Avengers, and even keeps Tony's language in line. Even when he and Iron Man were fighting in Civil War, Captain America was still a hero.

For those who have read the comic series, there is a bit of a disconnect....Captain America is a hero until the end, and there is an end. Captain America dies. In "The Death of Captain America", Cap is taken into custody and assassinated on the orders of his arch enemy, Red Skull. As a final blow, a brainwashed Sharon Carter delivers the killing shot. Hopefully we never have to see Captain America be murdered on the big screen.