Superhero comic books are often like soap operas (or pro-wrestling, if that's your thing) — filled with melodrama, dramatic twists, and characters once known as heroes turning heel and breaking bad.
This is a longstanding tradition, from decades old comic book to DC's recent 'Year of the Villain' which included heroes becoming 'infected' by the Batman Who Laughs and turning into villains.
But that's just the tip of the iceberg. Here are 10 of the most notable cases of superheroes-gone-villain.
The Viltrumite alien race is not known for their heroes.
When they sent one of their own to Earth, he apparently came to take care of the humans as their greatest protector. As 'Nolan Grayson,' the alien visitor had a wife and a son, Mark.
Mark began his career as the superhero Invincible, excited to fight by his father's side. However, his father turned against him, revealed as the herald of the conquering race. Mark didn't take too kindly to the betrayal, and he took even less kindly to the severe, near-death beatdown daddy dearest gave him as a parting shot.
Omni-Man's betrayal wasn't as whole-hog as it looked though, and his story was far from over, with the character returning several times throughout the series, as both villain and hero. The ideal that he once represented even inspired his second son, Oliver, to take up the name 'Kid Omni-Man' once he became a hero.
Superboy-Prime's story is somewhat familiar at first, centering on a young Kryptonian named Kal-El being sent to Earth as Krypton is destroyed. However, the particular Earth on which he arrives doesn't have any superheroes — it's kinda sorta meant to be the 'real' world.
It does have a comic publisher named DC, and that company publishes the stories of many heroes, like Batman, Green Lantern, and the greatest hero of all, Superman!
When a baby boy is found by a family with the surname Kent, they adopt him and name him Clark, despite the father's misgivings about the referential name. When his powers kick in (conveniently while he's in a Superboy costume for Halloween), Clark lives up to his name and helps save the universe during Crisis on Infinite Earths.
After Crisis, the Superboy from Earth-Prime is sent to a "paradise dimension" with several other heroes. Unfortunately, it wasn't a paradise to the young Clark. He went batty watching the heroes of the new Earth falling into darker and darker times, getting so angry that he punched his way through a wall of reality to break out of his prison (retconning DC history along the way).
What followed was an era of carnage at the hands of Superboy-Prime as he tore across multiple realities, joining the villainous Yellow Lanterns and even menacing the Legion of Super-Heroes in the guise of the Time Trapper.
Superboy-Prime recently returned to the DC Universe after having been trapped in the Source Wall for years.
While not a superhero per se, Jean Loring's betrayal is certainly legendary.
In an extremely misguided attempt to repair her relationship with Ray Palmer (a.k.a. the Atom), Loring lost it. She thought that by hurting another hero's wife, Ray would want to take care of her again. Donning his shrink-belt, she hopped into the brain of Sue Dibny, wife of the Elongated Man. She only intended to hurt Sue, letting her recover while everything was hunky-dory with Ray, but kicked a little too hard.
Sue, and the baby she was carrying, died, and Jean did what any violent murderer in the situation would do — she burned the body and ran away.
Jean made matters worse throughout the story of Identity Crisis, directly leading to the death of Tim Drake (Robin)'s father, as well as the death of the villain Captain Boomerang.
Jean's descent into villainy doesn't end there, though. She later became the villain Eclipso, and finally, after being eaten by a shark, came back as a Black Lantern (damn dirty zombies!) and killed the hero Damage.
Jean hasn't returned since DC rebooted with Flashpoint, and the events of Identity Crisis remain mostly unreferenced in modern continuity.
Jason Todd / Robin
Oh, poor Jason Todd.
Back in 1988, DC tried something a little different. Letting fans vote via a 900 number as to whether the second Robin would live or die, they found out comic book fans, while always are actually quite bloodthirsty.
When the vote came in to kill off the character, DC followed through, letting the Joker beat him down and blow him up. Then our number nine entry Superboy Prime punched reality, and Jason Todd came back to life.
Feeling betrayed by Batman for letting him die and for not avenging him by killing Joker, Jason decided to show him how he could do the job better.
While never going 100% down the villainous path (though he did get started by menacing Batman), Todd's methods since his return have been less than heroic. He is more than willing to kill his enemies, from low-level thugs to supervillains.
While Jason has narrowly tiptoed the line of the righteous, since the advent of the New 52 he's been chaotic good, so to speak, and has continued his anti-hero career across multiple titles in recent years.
James "Logan" Howlett has never been a very nice guy. Alive since 1882, Wolverine has fought for various armies, special forces units, and superhero teams, usually doing what it is he's best at — killing people.
But with a fractured mind from multiple wipes and memory implants, he has also been horribly susceptible to brainwashing. In fact, since the '90s, Wolverine has been pitted against his friends in the X-Men not once, not twice, but numerous times.
The first was as Apocalypse's Horseman of Death, the next thanks to Hydra and the Hand, and the finally time, he was sent to hell, with his body possessed by a demon.
A few years later, Wolverine went deep-cover with a villainous organization in an attempt to take down a larger villainous organization, too.
This was also the case in the 'Old Man Logan' timeline, where Mysterio tricked Logan into murdering the rest of the X-Men.
A bit of a "gimme" on this list, Wolverine technically hasn't gone bad of his own volition. However, his feral nature and willingness to kill when operating as a good guy certainly has something to do with it being so easy to turn him into a bad one.
Terra and Jericho
The Teen Titans is not the team to join if you're worried about being betrayed.
In the New Teen Titans era, they were betrayed by members of their team twice, both of whom had close connections to Deathstroke the Terminator.
The first, Terra, was always intended to be a traitor by her creators Marv Wolfman and George Perez, unbeknownst to readers or her teammates. She was only with the team for a short time, soon revealing her secret alliance (and extremely gross relationship...ew) with Deathstroke, helping him capture the team. With the help of Jericho, Deathstroke's son, the team broke free and her own rampage left her crushed under a building.
Jericho, however, also turned against the Titans. But his betrayal wasn't caused by his father, but by his teammate Raven's dad, the demon Trigon. Trigon possessed Jericho – who managed to fight Trigon off just long enough for Deathstroke to kill his own son, setting him free.
Like most comic book characters, he wouldn't stay dead, and has returned multiple times as both a villain, and more occasionally, a hero.
When the Runaways left behind their supervillain parents, the Pride, they vowed to help each other and never become like the bad guys that raised them. Unfortunately for them, they had a mole in their group — one of their own who broke that vow.
After journeying together for some time, Alex, the de facto leader of the group, manipulates the entire team into handing over their weapons to him. Armed with Chase's fistigons, Gert's telepathically controlled raptor Old Lace, and Nico's magical Staff of One, he easily takes down the last member, Karolina, and reveals himself as the traitor — a spy tracking them for the Pride.
Alex's intentions for his betrayal are at least someone noble – he's got a chance to bring himself, his parents, his crush Nico, and her parents into a safe zone that will survive the Pride's destructive plans.
However, Nico is unwilling to betray her friends and clashes with Alex, who dies in the ensuing fight.
In typical comic book fashion, Alex later came back from the dead to play a new, still villainous role in the Marvel Universe.
Hal Jordan / Green Lantern
At times, Hal Jordan has been called the greatest Green Lantern. At others, though, he's been their worst enemy.
In the storyline 'Emerald Twilight,' Hal uses his ring to recreate his recently destroyed hometown Coast City. Despite Hal's grief, the Guardians say that's a no-no — so Hal does what anyone would do in that situation: snaps completely, killing all his friends, stealing their power rings, and absorbing all of the power from the Central Power Battery of Oa.
Calling himself Parallax (later revealed as the name of the living embodiment of fear, which was previously imprisoned in the Power Battery), he continued his rampage, killing and severely injuring several others, until eventually sacrificing his life to reignite Earth's Sun.
Of course, he was subsequently absolved of just about all culpability, returned to life and again became DC's main Green Lantern. But despite what followed, Hal's descent stands as one of the most controversial comic book events in superhero history.
Jean Grey / Marvel Girl
Jean Grey and the Phoenix are intertwined.
When Jean Grey apparently died saving the rest of her team from a shuttle crash, she emerged from the depths of the ocean in X-Men #101 as the Phoenix, an incredibly powerful being.
She maintained her new power level as a hero for about two years, before the Hellfire Club started messing with her mind, with the telepathic Mastermind brainwashing her into betraying the X-men. Unfortunately, when Phoenix finally gives in to the idea of total power, she is far too powerful for the likes of Mastermind to control, and teleports to the far reaches of space. There, she eats a star, killing billions of the star system's inhabitants.
Powering down from her Phoenix form, Jean Grey is held on trial by the Shi'Ar – who clash with the X-Men as they try to save her. In the ensuing conflict, Cyclops is injured, leading Jean to go Dark Phoenix once again. After taking on the Shi'Ar, Jean gains control again, and sacrifices herself to defeat the Phoenix.
True to the Phoenix moniker, Jean was resurrected a few years later – sparking the trend of comic book death and return that continues to this day.
Steve Rogers / Captain America
Under the power of the Red Skull's influence thanks to the machinations of a sentient Cosmic Cube that re-wrote part of his history, the one-time Captain America Steve Rogers turned his back on the ideals of he spent his life fighting for and became a secret agent of Hydra.
Worse, Rogers (now fully committed to Hydra thanks to Red Skull's brainwashing) launched an attack that overtook the United States, turning it into Hydra's "Secret Empire."
Following the return of the 'true' Steve Rogers from the realm inside the Cosmic Cube, evil Steve - or 'Stevil' - was soundly defeated and is now imprisoned inside a secret facility, barely glimpsed since the end of Secret Empire.