To the initiated, Mysterio may seem like any other Spider-Man villain, but to those who know the fishbowl headed illusionist, he is known as one of Spidey's most sinister foes. But beyond simply being a cunning trickster and con-man, Mysterio has committed some frankly terrible atrocities throughout the years. Murder, deception, manipulation. No crime is too terrible for this villain.

When looking across all the Marvel Multiverse, it is clear that Mysterio has done some pretty awful, downright diabolical stuff. If one waded down the history of comics—knowing full well there are spoilers for decades worth of super-villainyy—one would discover Mysterio isn't just an ordinary goofy villain. Mysterio is one of the most sinister characters to ever grace comics.

10. Convincing Spider-Man Aunt May Died

Aunt May has died in the comics numerous times, but one of the "first" was in Amazing Spider-Man 196. However, it turns out that Peter's aunt wasn't dead at all.

The burglar who killed Uncle Ben, it turns out, had broken into the Parker home looking for old mob money. Mysterio faked the death of Aunt May to "allow" the burglar access to the money — all, of course, for a share of the money himself. While the burglar ends up dying of a heart attack by the end of Amazing Spider-Man 200, Mysterio successfully brought Spider-Man's world crashing down. Despite getting a bit of a beating, he walked away almost completely free.

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9. Grim Hunt

It took the blood of Spider-Man to raise Sergei Kravinoff from the grave. And while Mysterio wasn't the grand architect of the scheme, he sure played a vital role in bringing his former Sinister Six teammate to life.

Recruited to help lure Spider-Man into a trap, Mysterio—along with the Chameleon—convince Spider-Man to enter into a ritual in order to save Mattie Franklin (Spider-Woman) from the Kravinoffs. The Chameleon disguises himself as Peter's mentor Ezekiel, but it turns out to be an elaborate illusion which could only be pulled off with the help of Mysterio.

The horror of the Grim Hunt is not Mysterio's complete brainchild, which keeps this moment lower on the list. Still, he played a crucial, brutal part in the scheme.

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8. Turning Spider-Man Into Public Enemy Number One

One of Mysterio's most sinister plots also was his first. Amazing Spider-Man 13 marks Mysterio's first appearance, as well as one of his most infamous crimes.

Posing as the web-head, Mysterio committed various crimes, stealing and robbing people in broad daylight. This delighted JJ, as it finally validated his agenda against the wall-crawler. As the city converged on Spider-Man, a new "hero" named Mysterio emerged to capture the wall-crawler — all for a price.

While the scheme failed, there is something to be said in regards for the sinister danger posed by a villain who can turn the whole world against someone.

7. Killing The Kingpin

After returning from Hell itself, Mysterio set about a plot to conquer the Ultimate Universe. Sending an android avatar of himself into this other world, he took advantage of the events of Ultimatum to conquer the Ultimate's world of crime.

He did this by killing the Kingpin and taking over his criminal enterprise. He then committed a series of crimes that consisted of simulating a Hulk rampage across NYC, nearly bringing Spider-Man to the brink of death.

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6. Sending A Spider-Slayer To Peter's School

After the prior events, Mysterio found that he possessed trace amounts of Spider-Man's blood. Using his technology, he figured out Peter Parker's identity. However, he didn't seem dismayed to find that this universe's version of his ultimate adversary was, in fact, a child.

He created a Spider-Slayer designed to track Peter down by his DNA in order to kill him once and for all. Mysterio wasn't out for money, nor was he out to further his position. He just wanted to murder a teenage boy — and he did this by unleashing the Spider-Slayer in Peter's high school.

5. Holding The World Hostage

Mysterio is first and foremost a showman, and threatening the world with a biological agent seems in many respects to be quite the showstopper.

In the events of the "Return of the Sinister Six" arc (Amazing Spider-Man 334-339), Doctor Octopus reunites the Sinister Six in order to enact an insidious plot to threaten the world with a global poison. That is unless, of course, the world governments pay them a massive sum of money.

While it turns out that Doc Ock has a very different plot in mind, four of the five recruited villains seem perfectly content with poisoning the entire world if it means earning them a little extra money, including, Mysterio. In fact, when the Sandman finally turns against the Six, Mysterio loses no sleep turning against his former companion.

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4. Driving Spider-Man Mad

It figures that a master of illusions would do his best to drive the web-head nuts. But, in one of his first appearances, Mysterio deliberately drove Spidey into madness.

Posing as a doctor, Mysterio goes to the Daily Bugle to tell the public that Spider-Man has developed a second personality that will lead to the web-head losing his mind. Believing "the doctor," Spider-Man finds himself running into "hallucinations" of his rogues' gallery; all while running around a funhouse full of furniture sticking to walls and other mind-bending illusions. It turns out the whole thing was staged by Mysterio. If not for the interruption of Jameson himself, Mysterio would have convinced Spider-Man to reveal his secret identity to "the doctor" in order to be "treated for his split personality."

3. Sending J. Jonah Jameson To Hell

While J. Jonah Jameson is not a lovable oaf, he has done enough to become a likable entry in Spider-Man's extended cast of characters. While Mysterio didn't actually send JJ to Hell, he sure made him think so.

In Webspinners: Tales of Spider-Man #1-3, Mysterio entraps JJ in an illusion, convincing the Daily Bugle tycoon that he's trapped in Hell. To make matters worse, all the demons are Spider-Man pestering him for all eternity.

While no lasting harm was done to JJ, the idea of creating a living Hell for another human being is nothing short of sinister.

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2. Killing Karen Page

Mysterio is often regarded as a Spider-Man villain, yet some of his worst crimes were committed against villains adjacent to the web-head. Case in point, the Kevin Smith-penned story arc "Guardian Devil."

It turns out Mysterio, after years of breathing in his signature gas, had developed cancer. Determined to go out with a bang rather than a whimper, he decided to get killed by a "second-rate" character like Daredevil, thus concocted a scheme that led to Matt Murdock believing a child he is handed (by Mysterio in disguise) is actually the Antichrist. Along the way, Mysterio purchases Matt's secret identity from the Kingpin, after which he sends Bullseye to kill the love of Matt Murdock's life, Karen Page.

All this to drive Daredevil to kill him, which ultimately fails to push Daredevil to murder, leaving Mysterio to end his life on his own terms.

1. Killing The X-Men

Mysterio's greatest illusion lead to the death of the entire X-Men.

In the alternate continuity of Old Man Logan, Wolverine is haunted by his sins. Some time prior, he had entered a berserker rage and convinced his mortal enemies were attacking the X-Men.

However, it turned out to all be a clever rouse by Mysterio, who used his illusions to turn a berserk Wolverine on his fellow mutants. All of them. By the time the illusion faded, Wolverine was left gazing into the eyes of his victims: his family gored and bloodied under his own claws.

Mysterio may be many things, but this is the first and arguably only time he took down a group of major heroes in such a sadistic fashion.

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