Often fans look at superheroes as paragons of virtue, but much like the gods of Greek myth, they have proven how truly flawed they can be, countless times. Mostly this entails them failing in their mission, but sometimes it means that they fall into darkness.
The story of a hero turning bad isn't a new trend in comics, but it always has the potential to spawn some really great stories. With all that said, though, not every heel turn that the likes of DC and Marvel have crafted has been gold, in fact, some have proven to be absolute duds.
Great: Captain America (Secret Empire)
Controversial upon its genesis, Captain America's tenure as a Hydra sleeper agent is a fascinating period to look back on. Though fans had a knee-jerk reaction to the change from some of the more emotionally trigger-happy fans, Cap saying "Hail Hydra" and leading an evil takeover of America was mostly well-written and cool.
Steve Rogers' villainous run ranks low here because Marvel got cold feet and had it revealed that this Cap wasn't the real McCoy. Though Secret Empire's ending is disappointing, the fallout of Steve's time with Hydra is still in play to this day.
Failed: Wally West (Heroes In Crisis)
Two years was all it took for DC to ruin Wally West's glorious return. If it wasn't bad enough that the divisive event Heroes In Crisis kicked off with Superman finding Wally's dead body among a cornucopia of dead superheroes, but the twist that he was the killer completely turned fans off.
The turn made literally no sense and felt extremely mean-spirited on the creative end. From this story on, creators had to bend over backward in order to redeem Wally after the controversial decision to make him a murderer did nothing but alienate people.
Great: Jason Todd (Under The Hood)
For the longest time, Jason Todd's legacy was completely boiled down to a costume in a case in The Batcave. That all changed when the character was brought back in "Under The Hood," making the former Robin the new top dog villain.
Jason's debut as The Red Hood set the precedent for what his life would be from then on, with his villainous tactics working to both terrorize the criminal element in Gotham and disturb his former mentor, Batman. Nowadays, Jason flirts with more traditional heroism, but his villainous debut worked gangbusters.
Failed: Spider-Man (Superior Spider-Man)
Some look at Spider-Man's body being taken over by Doctor Octopus in the acclaimed story Superior Spider-Man as Spidey turning bad. If that's the case, then the turn was a total failure, as it was more of a story of Doc Ock seeing the light.
When a dying Otto Octavious swapped bodies with Spidey, he barely got a chance to do anything really bad before Spidey gave Otto his memories. Otto then learned that with great power comes great responsibility and became a good guy from that day on.
Great: Iron Man (Axis)
Axis wasn't the first time Iron Man broke bad, but it was by far the most successful time. Inverted by Red Onslaught, Tony created a new version of Extremis with the intent to use it to prey on those with disabilities.
Not only did Tony charge an insane price for the app, but his actions perpetuated a massive crime wave just to get the money to use it. Iron Man's villainous run was fun for fans to read and it probably made those with the Marvel Universe happy that he's on their side.
Failed: Cassandra Cain (One Year Later)
Quite a few people would regard Cassandra Cain as the best Batgirl, but her status post-Infinite Crisis rubbed many fans the wrong way. Trained to be one of the greatest assassins at the expense of being able to speak, Cassandra Cain's journey from killer to hero was one that fans grew attached to, making her fall from grace all the more painful.
Now the leader of The League of Assassins in the One Year Later era, Cassandra not only murdered a whole lot of people, but she also joined Deathstroke's more sinister Teen Titans team. This period of Cassandra's life is as controversial, as it was mercifully brief.
Great: Bucky Barnes (The Winter Soldier)
Bucky Barnes' return to life echoes that of Jason Todd, which makes sense as both their resurrections took place around the same time, but the circumstances of his return are far more harrowing. "The Winter Soldier" storyline revealed that Captain America's former sidekick had never died, instead he was brainwashed and turned into The Soviet Union's private assassin.
The twist was a nice surprise, with the impact of Bucky's current status having a gut-wrenching impact on an already mentally fragile Captain America. Even though Bucky's memories would soon be restored, "The Winter Soldier" changed him forever.
Failed: Jean Grey (The Dark Phoenix Saga)
Much like Superior Spider-Man, "The Dark Phoenix Saga" is a phenomenal story with a villainous turn that falls flat. Longtime X-Men member Jean Grey becoming The Dark Phoenix is one of the most iconic things the character has ever done, but at no point was she in control of her actions.
The worst things that The Phoenix Force caused Jean to do were their actions and theirs alone, Jean had nothing to do with the atrocities that The Dark Phoenix is responsible for. Unfortunately, Jean never got a chance to prove her innocence, because she sacrificed herself to stop the conflict between The X-Men and The Shi'ar.
Great: Superboy-Prime (Infinite Crisis)
Debuting as a saint in Crisis on Infinite Earths, fans became more invested in Superboy-Prime when Infinite Crisis turned him into a sinner. Infuriated that he had lost his reality in the era following Crisis, Superboy-Prime, an alternate version of Superman, went on a rampage that would affect reality.
During Superboy-Prime's epic rampage, he delivered a punch that literally shook reality and would cause some very major ripple effects. Among the changes made by Superboy-Prime's included Jason Todd's resurrection, which would later be retconned.
Failed: Captain Atom (Countdown)
If a heel turn is forgettable, then what was the point of it? That is the question posed by Captain Atom becoming the villain Monarch in Countdown, the loathed event that was written to lead up to Final Crisis. Though Atom becoming Monarch failed, it's a failure with some history.
In the equally bad event, Armageddon 2001, the main villain Monarch was supposed to be revealed to be a future version of Captain Atom, but when the ending was leaked to fans, Monarch was revealed to be Hawk from Hawk and Dove. Countdown attempted to remedy this error, it's just a shame that nobody cared.