The the Juggernaut is actually a member of the X-Men.

However, the Juggernaut’s journey from villain to hero wasn’t a straight line, as Cain Marko rode that line for many years before finally becoming a full-fledged superhero. And, when he did become a hero, the Juggernaut had a lot to make up for. Juggernaut didn’t just terrorize the X-Men back when he was a villain, but the entire Marvel Universe - including innocent civilians who felt his unstoppable wrath.

The Juggernaut’s past doesn’t detract from the hero he is today, but it’s also important to where he came from before continuing to watch his story progress. That being said, here are the 5 times Juggernaut proved he was a hero, and 5 times he lost the dark side win.

10 BAD: Secret Murder Spree

Cain Marko Murdered Innocent People the Moment He Became the Juggernaut

One of the worst things the Juggernaut has ever done happened within the first few moments of Cain Marko becoming the Juggernaut. As revealed in New Excalibur #15, Cain Marko didn't just become the Juggernaut, he had to win that title in battle by killing the previous avatar of Cyttorak. Once he did so, Marko had to prove his loyalty to Cyttorak if he wanted to keep his Juggernaut power, and he proved himself by murdering an entire village.

Cyttorak wanted this village to pay for the crime of no longer worshiping him, and he used his new avatar to do it. In fact, that's why Cain Marko was allowed the chance to challenge the previous Juggernaut, as he wouldn't carry out this grisly task. However, Marko was totally fine with it, and while he'd regret it later, he still went on a murder spree.

9 GOOD: Befriended Squid Boy

The Juggernaut Formed a Father/Son Relationship with a Mutant Named Squid Boy

During one instance when the Juggernaut was seeking redemption, he went to the X-Mansion to tell Charles Xavier that he was at the X-Men's disposal. When he's there, the Juggernaut meets a ten-year-old mutant named Sam Paré aka Squid Boy, and before long, the Juggernaut decides to take him under his wing. The Juggernaut sees how Squid Boy is different even among other outcasts, and he wants to help him through this difficult time in his life.

Unfortunately, when the Juggernaut goes on an undercover mission that makes it seem like he went back to his life as a villain, Squid Boy thinks his surrogate father abandoned him. Squid Boy tragically dies shortly afterward, hating the Juggernaut with his final breath. This story ends in tragedy, which only highlights how much the Juggernaut genuinely cared for Squid Boy, proving he is a good person.

8 BAD: Conquered an Entire Alien Society

The Juggernaut was Banished Off-World by Thor, & Proceeded to Take Over an Alien World

A prime example of how the Juggernaut was more than just an 'X-Men villain', but a scourge on the entire Marvel Universe, Thor #429 details how Cain Marko once took over an entire alien society. A few issues prior (in Thor #412), Thor banished the Juggernaut from Earth, as he was deemed too dangerous to remain there. Thor stranded Juggernaut on an asteroid, but a ship of kind aliens picked him up and brought him to their planet - and that proved to be a big mistake.

The Juggernaut was so evil back then that he didn't even want to have a fresh start among aliens who showed him kindness after being banished from Earth. Marko saw this only as another opportunity to be evil, and he took it by taking over the whole planet.

7 GOOD: Voted onto the X-Men

The Juggernaut was Voted onto the Main X-Men Team by Mutants (Despite Not Being One)

During the X-Men's final Hellfire Gala, all of mutantkind was given the opportunity to vote for who they wanted to be on the flagship X-Men team. At the time, the X-Men represented the best of mutantkind; the ultimate heroes of their race and nation. Other X-Teams existed, of course, but the X-Men was the most prestigious team - and the mutants decided that the Juggernaut deserved to be on it.

This came after the Juggernaut proved himself a hero of Krakoa for many years, so it was well-earned. But, it is still a testament to how good the Juggernaut became, as it wasn't just something he was working on within himself, but his goodness was obvious to those around him. The Juggernaut earned his redemption, and he's still an official member of the main X-Men team to this day.

6 BAD: Attempted to Murder the X-Men When They Were Kids

The Juggernaut's First Fight Against the X-Men was When They were Children

Long before he became a part of the X-Men, the Juggernaut made a name for himself as their enemy. Unfortunately, he became their enemy back when the X-Men were still just a bunch of teenagers (as opposed to the adults they've been since the '80s). That means the Juggernaut basically assaulted children during his first fight with the X-Men. More than that, the Juggernaut clearly meant to kill them along with his stepbrother, Charles Xavier - so go ahead and add attempted murder to that assaulting a minor charge.

This is one of those things that's almost comical when one thinks about it. When fans first read this comic, all they saw was the X-Men fighting an especially tough villain-of-the-week. They didn't consider that the villain in question was a lunatic assaulting children. But, that's exactly who the Juggernaut used to be, and that was decidedly bad.

5 GOOD: Saved Krakoa

The Juggernaut Saved Krakoa When No One Else Could

In The Fall of the House of X, one of the final chapters of the X-Men's Krakoan Age, the Juggernaut is dragging what remains of the mutant island nation of Krakoa across a desolate desert, hiding it from those who wish the island-mutant's destruction. At this point, Orchis - led by the seemingly unbeatable Nimrod - was on the verge of wiping out muntantkind, and anyone else who stood with them.

That meant the Juggernaut's mission was all but doomed from the start, as he would likely die along with Krakoa. But, Juggernaut didn't care, and instead did what no one else could do: save Krakoa. The Juggernaut dragged what remained of the island-mutant as far from civilization as possible, hoping that would be enough to protect it. And, in the end, his mission was successful, as Krakoa survived this conflict because of the Juggernaut.

4 BAD: Doomed the Human (& Mutant) Race

The Juggernaut was to Blame for the Sentinels Wiping Out Humanity

While this version of the Juggernaut is from another reality (only appearing in a What If...? comic), this Juggernaut's actions stem from those of his Earth-616 counterpart, so they still very much apply. In What If...? #94, the Juggernaut is successful in murdering Charles Xavier and most of the X-Men during his initial assault on the X-Mansion. That meant the X-Men weren't around to expose the Sentinel Program, allowing the Sentinels to become immensely powerful in secret.

These Sentinels brought about a Days of Future Past-esque future in this alternate reality, resulting in the decimation of the entire human (and mutant) race. And, as Magneto points out to Marko during their battle in this issue, it was all the Juggernaut's fault. Sure, Juggernaut feels bad and destroys the Sentinels for what they did, but by then, the damage was done.

3 GOOD: Has Made Himself a Target

The Juggernaut Wears a Big Red 'X' on His Helmet to Draw Villains' Attention

Not only has the Juggernaut proved that he's a good guy now by being a member of the X-Men, but he proves it further with his new X-Men costume. The Juggernaut had a bit of a redesign once he became a main X-Men member, with the most notable being the big red 'X' on his helmet. At first, it just seemed like the Juggernaut simply wanted to include an 'X' somewhere on his armor to indicate that he's now an X-Man. However, while battling a villain named Orifice, the real reason is revealed - and it's way more heroic.

The Juggernaut wears an 'X' on his helmet to make himself a target during battle. Marko wants to draw villains' attention to him and away from his teammates to ensure their safety even in the middle of a fight.

2 BAD: A Life-Long Bully

Cain Marko was a Bully as a Child, Which He Carried Into Adulthood as the Juggernaut

While it may seem petty to hold the actions of someone's childhood against them into adulthood, it's actually an important point to make in this case, especially when considering how and why the Juggernaut became a villain in the first place. As a boy, Cain Marko was a cruel bully who picked on anyone who he deemed weaker than himself - including and especially Charles Xavier. In fact, Marko was responsible for crippling Charles - that's how severe his bullying was.

Cain Marko didn't outgrow this character flaw, either, as his bullying ways were why he agreed to become an avatar for a demon-god, and ultimately, why he became a villain in the first place. A lot of people had to suffer because Cain Marko refused to mature once he became an adult, and that's something he still needs to make up for.

1 GOOD: Saved D-Cel

The Juggernaut Takes a Mutant Under His Wing who Would Have Been Left Behind by the X-Men

Just like when he took Squid Boy under his wing, the Juggernaut also helped another mutant teenager who needed him: D-Cel. D-Cel has the mutant power to create deceleration fields, which are strong enough to stop the Hulk and the Juggernaut himself. However, her powers also have one catch: they make her untraceable to telepaths - even if they're using Cerebro. That meant the X-Men couldn't invite her to them on Krakoa (where she desperately needed to be, as she was introduced as a self-hating mutant because of her powers).

The Juggernaut was D-Cel's ticket to Krakoa, and to a better life for herself among her own people. Without the Juggernaut this teenager could have fallen into a pit of depression from which there might have been no escape, making the fact that he took her in a very good thing, indeed.