While the trailers for Spider-Man: Far From Home portray Jake Gyllenhaal's character Mysterio as a new hero in the Marvel Cinematic Universe. Mysterio reveals he's a hero from another Earth in the Marvel Multiverse, but a hero, nonetheless. Of course, comic fans know Mysterio is anything but heroic, even if he is from an alternate reality.

RELATED: How Mysterio Crossed Dimensions in Marvel's Ultimate Spider-Man

Mysterio has done some terrible things over his career, which began as a special effects wizard in Hollywood before Quentin Beck put a fishbowl on his head and started elaborately pranking people. So before we buy into the MCU's newest hero, let's look back at a few of the worst things Mysterio has ever done in the comics.

10 FRAMED SPIDER-MAN IN HIS FIRST APPEARANCE

J. Jonah Jameson had a field day when Spider-Man turns to a life of crime and robs the Midtown Museum in Amazing Spider-Man #13, but as tends to be the case whenever Mysterio shows up, things aren't as they seemed. The criminal Spider-Man was actually Mysterio in disguise, using his effects tech to simulate Spider-Man's abilities.

Mysterio even manages to defeat Spider-Man in their first encounter, using pre-arranged gimmicks and a concealing mist that manages to dull Spider-Man's spider-sense. However, Mysterio couldn't keep himself from monologuing and confesses to the impersonation before getting sent to jail by Spidey, launching his long feud with the webhead.

9 FAKED AUNT MAY'S DEATH

It's amazing how many times Aunt May has coincidentally been put in jeopardy by Spider-Man's villains, given that her connection to Spidey is largely unknown. Yet, beginning in Amazing Spider-Man #195, Mysterio faked Aunt May's death, which drops Peter into a dark hole for a few issues.

RELATED: Spider-Man Handles Aunt May's Secret in the Worst (and Best) Way Possible

The reason for the con by Mysterio is financially motivated and actually involves the burglar who murdered Uncle Ben, which makes the faking of Aunt May's death seem trivial from their perspective. It's the emotional heartbreak felt by Peter Parker that really proves why this is one of the worst things Mysterio has ever done.

8 ALMOST DROVE SPIDER-MAN INSANE

During the previous plot discussed, Beck uses the alias of Dr. Ludwig Rinehart to trick Peter Parker about May's supposed death. Due to Peter's sorrow over his aunt's apparent passing, he fails to remember that Mysterio had previously used this exact name, as he had been wearing a mask at the time.

Dr. Rinehart reaches Spider-Man through the Daily Bugle, who is told the wall-crawler could be in store for an emotional break unless treated by the good doctor. Once Rinehart meets Spider-Man, he used his FX wizardry to convince Spider-Man that he was going insane in order to reveal his secret identity. The day was actually saved by J. Jonah Jameson, who had discovered Rinehart was a phony.

7 CAUSED KAREN PAGE'S PASSING

While Mysterio spent many years fighting against Spider-Man while trying to prove himself as the master of illusions, it wasn't until he decided to test his mettle against another hero that we saw how far Mysterio was willing to go. During the "Guardian Devil" storyline, Mysterio learns he is dying from cancer-related to exposure to his own effects and decides to go out with a bang.

RELATED: Spider-Man: Far From Home's Mysterio Once Nearly Drove Daredevil Insane

Due to Spider-Man being unavailable, the villain sets his sight on Daredevil, learns his secret identity, and systematically derails not only Matt Murdock's life but his closest friends as well. He also unleashes the assassin Bullseye, who murders Karen Page during a battle with Daredevil.

6 HELPED MURDER KAINE PARKER

At the climax of his plot against Daredevil, the terminally-ill Quentin Beck followed in the footsteps of fellow Spidey-villain Kraven the Hunter and took his own life with a gun. Of course, comic book deaths never really stick, and Mysterio soon returned, after apparently making a deal with the devil in Hell.

During the "Grim Hunt" storyline, Mysterio plays a small role in the resurrection of Kraven the Hunter, perhaps due to his smudging of Kraven's legacy with his previous copied suicide attempt. During the ritual to bring back Kraven, Mysterio and Kraven's family eliminate Kaine Parker, believing the clone to be the real Spider-Man.

5 MURDERED ULTIMATE KINGPIN

In Spider-Man: Far From Home, Mysterio's claims of being from an alternate Earth are rooted in his comic past. At one point, Mysterio operated in another reality known as the Ultimate Universe, where the villain used an interdimensional portal to remotely control an android, becoming his own alternate reality counterpart.

RELATED: Spider-Man: Far From Home's European Trip Could Be Bad News For Ned

Ultimate Mysterio endeavored to become a crime boss, and in one of his earliest appearances in the Ultimate universe, Mysterio blasted Ultimate Kingpin out of Fisk Towers to fall to his death. Mysterio's anonymity in the Ultimate Universe only seemed to have brought out the worst in the villain.

4 UNLEASHED A SPIDER-SLAYER INSIDE A HIGH SCHOOL

Shortly after he murdered the Ultimate Kingpin, Mysterio managed to get a sample of the Ultimate Spider-Man's blood, who was younger than the Spidey Mysterio had faced for so many years. He was able to track down Peter Parker using this blood sample and unleashed a deadly robotic spider-slayer on his location - Midtown High.

While the spider-slayer was destroyed by the Ultimate Human Torch and Shroud (Kitty Pryde), it managed to capture footage of Spider-Man's secret identity, which makes Mysterio part of the elite group of people who know the truth about Peter Parker.

3 HELD THE WORLD HOSTAGE WITH THE SINISTER SIX

Mysterio has worked alongside the Sinister Six since their very first appearance in 1964's Amazing Spider-Man Annual #1, though he hasn't been a part of every iteration. He did rejoin the Six during the "Ends of the Earth" storyline under the leadership of Doctor Octopus.

RELATED: Spider-Man: Far From Home Isn't Setting Up the Sinister Six

The Six held the planet hostage with an array of satellites that could rapidly speed up the greenhouse effect, which could have killed millions. While Mysterio eventually turned on Doc Ock and helped Spider-Man and his allies save the day, he only did so when he realized he probably wouldn't get the payday he was promised.

2 SACRIFICED HIS "DAUGHTER" FOR MYSTICAL POWER

Following Mysterio's resurrection and evil deeds in the Ultimate Universe, Quentin Beck managed to secretly relocate to Las Vegas and apparently retire from the criminal lifestyle. There he was hunted down by his daughter Misty, who was revealed to be a robot created by Beck in the past who believed herself to be his daughter.

Misty Beck/Mysteria brought her father along on a magic act before revealing the location to be an ancient mystical site of power, where she planned to sacrifice her father in order to gain mystical power. Quentin instead took out his daughter before empowering himself, albeit only briefly. Like father, like daughter.

1 TRICKED OLD MAN LOGAN INTO SLAYING THE X-MEN

MYSTERIO - Old Man Logan

The character of Old Man Logan hails from a possible future known as the Wasteland, which is a world in which the supervillains won. Logan has managed to raise a family and has put away his claws for good, following a traumatic encounter with Mysterio, of all people.

Prior to settling down and becoming a family man, Logan was responsible for the violent deaths of the X-Men, although Mysterio's illusions deserve most of the credit. While Wolverine thought he was battling the various villains of the X-Men, he was instead massacring his own friends. Mysterio has no limits.

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