Over the past 84 years, a lot of things have happened in the DC Universe. Through countless stories in comics, TV and film, heroes like Superman, Batman and Wonder Woman have defined what superheroes are in the general public's imagination. While the DCU might be filled with hundreds of beloved adventures, it's still seen more than its fair share of controversy over the years. As times and characters have evolved, many of these controversial ideas have led to lasting changes for iconic DC characters like Harley Quinn, the Flash and the Justice League. DC's most iconic heroes and villains. Especially over the last few decades, the worlds of DC have been home to numerous controversies that divided longtime fans and made headlines all around the world.

Now, CBR is taking a look at some controversial changes that shook the DC Universe to its core. In this list, we'll be counting down some of the biggest controversies about DC's characters in comics, TV and film, in no particular order. We'll also be looking at how these divisive storylines, plot twists, new costumes and other issues were, or weren't, addressed and how these controversial ideas reshaped DC's future plans. While DC has published hundreds of series through its various imprints, we'll be sticking to characters who are currently part of the main DCU, even if they didn't start out there. From totally forgotten storylines to major reboots, many of these controversies played a fundamental role in forming the DCU that fans know and love today.

25 BATMAN'S REPLACEMENT

Batman Knightfall Azrael

Today, plenty of characters like Dick Grayson and Terry McGinnis have been Batman, but Bruce Wayne had never really been replaced as Batman by the 1990s. When the just-introduced Jean-Paul Valley replaced Bruce as Batman in 1993 crossover "Knightfall," he turned Batman into a heavily-armored hero with lots of firepower.

While Bruce Wayne sat injured on the sidelines, Valley's Batman used ruthless tactics in a high-selling storyline that caused concerns among readers who were still mourning Superman. When it became clear that the point of the story was that no one could ever really replace Wayne as Batman, those concerns largely subsided. By the time the fondly-remembered story ended, Wayne's Batman returned, and Valley kept on fighting crime as the hero Azrael.

24 SUPERMAN SNAPS

Superman Man of Steel Henry Vacill

Even though he's the first superhero, Superman hasn't always had the best luck on film. While Christopher Reeve's Superman made audiences believe he could fly in 1978's Superman and stopped the Kryptonian General Zod in 1980's Superman II, Superman's later films were met with mixed success.

In 2013, director Zack Snyder showed audiences a different kind in Superman in Man of Steel.

While the movie was a box office success, Henry Cavill's Superman starred in a divisive film that many fans found uncharacteristically dark and dour. In its controversial climax, Superman permanently finished off Zod after part of Metropolis was reduced to ruins. After the equally divisive Batman v. Superman: Dawn of Justice, Cavill's Superman lightened up some by the end of 2017's Justice League.

23 HARLEY QUINN'S MAKEOVER

Harley Quinn Margot Robbie 2

After debuting in Batman: The Animated Series, Harley Quinn quickly turned into a fan-favorite villain with a striking red-and-black jester costume. When Harley joined the comic book DC Universe in 1999, she had the same iconic costume and kept it for years. When Rocksteady Studios redesigned Batman's rogues' gallery for its 2009 video game Batman: Arkham Asylum, Harley got a more revealing redesign that alienated some of the character's longtime fans.

When DC rebooted its comics with the New 52 in 2011, Harley got another revealing design that was based on her Arkham look. Despite early criticism, fans warmed up to the design as it evolved. By the time it was the basis for Margot Robbie's cinematic Harley Quinn, it was unquestionably Harley's definitive look.

22 GREEN LANTERN LOSES IT

Hal Jordan becomes Parallax

While there have been hundreds of Green Lanterns from across the universe, none of them is quite like Hal Jordan. The cosmic hero distinguished himself as the greatest member of the Green Lantern Corps through years of service.

That didn't stop Hal from turning into the power-mad villain Parallax in 1994.

This was the ultimate betrayal for fans, including those who formed Hal's Emerald Advancement Team, or H.E.A.T., who vigorously tried to convince DC to reinstate Hal as Green Lantern. While DC began to walk back Hal's villainous turn, he wasn't fully redeemed until 2004's Green Lantern: Rebirth. In that miniseries, Parallax was revealed to be a giant space bug that possessed Hal. Cleared of Parallax's crimes, Jordan promptly returned to his Green Lantern duties.

21 CONSTANTINE COMES HOME

John Constantine

The cynical sorcerer John Constantine was created by Alan Moore, Steve Bissette and John Totleben in 1984's Saga of the Swamp Thing #25. While that title and Constantine's solo series, Hellblazer, were technically part of the DC Universe, they were filled with adult-oriented "sophisticated suspense" that didn't quite fit in with DC's other titles.

When DC launched the mature readers Vertigo imprint in 1993, Constantine's series moved there, and he grew older as Hellblazer continued for 20 years. To Vertigo fans' dismay, Constantine returned to the DC Universe in the 2010 crossover Brightest Day and joined a Justice League within a year. In an odd case of life imitating art, Matt Ryan's Constantine joined the superhero-filled Arrowverse after his TV series was canceled in 2015.

20 THE NEW 52

New 52 Superman

In order to make sense of eight decades of stories, the DC Universe has gone through a few reboots meant to simplify its history and bring in new readers. While rebooting is always controversial, DC's 2011 reboot, the New 52, proved especially divisive among fans.

The New 52 was seemingly set to wipe away 25 years of DC history.

Almost every DC character went through major changes that all caused smaller controversies. While some pre-New 52 stories were still part of the rebooted universe's history, fans were confused about which stories still "counted." Although the New 52 was a commercial success, sales fell after a few years. Since 2016's DC Rebirth relaunch, more aspects of the pre-New 52 universe have been reintroduced in various storylines.

19 BATGIRL'S FALL AND RISE

Batgirl adam hughes

In one of the most controversial stories DC ever published, Barbara Gordon, the most famous Batgirl, was paralyzed by the Joker in 1988. Despite her injury, Gordon reappeared a few years later as the information broker Oracle. Even though she spent most of her time in a wheelchair, Oracle co-founded the Birds of Prey and joined the Justice League during this time.

While Gordon's role as Oracle was well-received, her overall arc drew increasing criticism in the intervening years. When DC launched the New 52 reboot, the publisher changed Barbara's history so that she recovered from the injury and resumed fighting crime as Batgirl. Although these developments also drew criticism from fans, Gordon's Batgirl quickly returned to her prominent spot among Gotham City's heroes.

18 SUPERMAN GOES ELECTRIC

Superman Electric Blue

Superman might have the most iconic costume in superhero comics. With its famous "S-shield" and its trademark red, blue and gold color scheme, it's an instantly recognizable all over the world. Naturally, some fans were upset when he traded that costume for a blue-and-white "containment suit" during a 1997 storyline.

Superman also developed energy-based powers that let him shoot electric blasts.

During Superman's blue period, he was also briefly split into separate red and blue bodies. While the event started out with a highly-publicized bang, the shock and novelty of a blue Superman wore off fairly quickly. In 1998, Superman got his old powers and costume back, and one of the odder chapters in the Man of Steel's history came to an end.

17 HARLEY AND IVY BREAK BAD (AGAIN)

Poison Ivy Harley Quinn

Even though they started out as Batman villains, characters like Catwoman, Harley Quinn and Poison Ivy have stood on their own as the stars of their own adventures. However, this has caused some problems. While they've usually acted like antiheroes in their solo stories, they've done horrible things that frustrate their fans when they've been used as villains again.

Just before Harley Quinn's light-hearted solo series started in 2013, she launched a devastating attack on Gotham City's most unsuspecting citizens during DC's "Villains Month" crossover. While Harley hasn't really embraced that kind of crime since, the rehabilitation of Poison Ivy has been an ongoing concern in Batman's recent adventures, where her occasional relapses into villainy have drawn the ire of some fans.

16 BEFORE WATCHMEN

Before Watchmen Rorsarch

Over 30 years after it was first published, Watchmen still lives up to the hype. Alan Moore and Dave Gibbons' dystopian masterpiece influenced generations of readers and creators with its distinctly adult take on superheroes.

Watchmen is still heralded as one of the most important comics ever published.

For decades, Watchmen was on a pedestal, where it stood untouched as the comic book medium's crowning achievement. But in 2012, DC announced Before Watchmen, a massive line of prequels that explored the world of Rorschach and Doctor Manhattan. Since Moore and Gibbons had a lengthy dispute with DC over the rights to Watchmen, the news did not sit well with many fans and creators. Although Gibbons gave the project his blessing, Before Watchmen ultimately received a mixed reception.

15 WONDER WOMAN GETS GROOVY

Secret Agent Wonder WOman

In an attempt to update Wonder Woman for the 1960s, the Amazon got an extreme makeover in 1968's Wonder Woman #178. Under Dennis O'Neil and Mike Sekowsky, Wonder Woman renounced her powers and became a secret agent. As the new owner of a trendy clothing boutique, she also ditched her classic costume for a selection of hip new ensembles.

Under the tutelage of the blind master martial artist I Ching, this James Bond-inspired Wonder Woman was also proficient in hand-to-hand combat. Numerous fans, including some prominent political figures, bemoaned the loss of Wonder Woman's classic look. While these widely-panned changes were walked back in 1973, Wonder Woman's days as a secret agent have occasionally been revisited since then.

14 BATMAN'S DARK RETURN

Micheal Keaton Batman pointing his grappling hook

With 1989's Batman, director Tim Burton introduced general audiences to a more serious version of the Dark Knight that was a far cry from Adam West's goofy Batman of the 1960s. For 1992's Batman Returns, Burton took Michael Keaton's Batman to operatic new heights in a darker, grimier Gotham City that was too much for some children who reportedly left the movie in tears.

Some parent groups even launched protests against Batman Returns.

Since McDonald's had "Happy Meal" toys that tied-in with the movie, the fast food giant received numerous complaints too. Despite mostly positive reviews, the protests still hurt the movie's total box office. This was partially why Burton left the franchise and why director Joel Schumacher's two follow-up Batman movies were more kid-friendly.

13 INFINITE CRISIS

The original Superman during Infinite Crisis

Due to the ever-changing nature of the DC Universe, the last time readers saw the Superman who was created by Jerry Siegel and Joe Shuster in 1938's Action Comics #1 was in 1986. At the end of the massive crossover Crisis on Infinite Earths, Superman helped defeat the villain who was destroying reality and walked into an eternal paradise with Lois Lane.

Then, Infinite Crisis happened. In that 2005 crossover, Superman and his allies escaped paradise to remake the DC Universe in their image, which put them at odds with DC's other heroes. Since this version of Superman was the first superhero ever, some fans took issue with him becoming a villain. After coming to his sense, the original Superman perished while saving the world.

12 TEEN TITANS GO TO TV

Teen Titans GO jump into action

While the Teen Titans have starred in two of DC's most successful animated series, both of them debuted to some early criticism. In 2003, Teen Titans premiered with a unique anime-influenced visual style that disappointed fans who were hoping for a show set firmly in the DC Animated Universe. Despite those complaints, the show was still a massive critical and commercial success.

Teen Titans Go! also had to deal with uncertain fans when it launched in 2013.

This series turned the Teen Titans' daily lives and superhero adventures into a zany, fast-paced comedy. While this approach disappointed some fans of the previous Titans cartoon, the show has been staggeringly popular with young viewers, dominated Cartoon Network's schedule and inspired a well-reviewed feature film in 2018.

11 ROBIN'S LAST STAND

Batman Robin Jason Todd Batcave

When Jason Todd became Batman's second Robin in 1983, the young hero was pretty popular with fans. However, after he was given a revised origin with a troubled childhood, Batman fans soured on the sidekick. In an attempt to boost interest in Batman's adventures, DC editor Dennis O'Neil orchestrated an even where readers could call a hotline and vote on whether or not Jason would survive an upcoming storyline.

Unfortunately for Jason, he lost the vote and met an early demise at the hands of the Joker. This storyline made national headlines and drew heavy criticism. The legacy of Todd cast a shadow over Batman's adventures for years. However, Todd's story got a happy ending after he was revived as the Red Hood in 2005.

10 WONDER WOMAN'S ODYSSEY

Wonder Woman Odyssey

Between 2010 and 2011, Wonder Woman's entire history was seemingly overwritten twice in one year. Like the rest of the DC Universe, Wonder Woman was rebooted by the New 52, but she almost went through another reboot in 2010's Wonder Woman #600. In the J. Michael Straczynski-penned storyline "Odyssey," Wonder Woman found herself in an alternate timeline where her Amazonian home was completely destroyed.

Wonder Woman forgot everything about her life and the rest of the world did too.

Wonder Woman also received a new costume that featured long pants and a leather jacket. This new ensemble divided fans and also made national headlines. After the story received a mixed reception, it was quickly forgotten in the wake of Wonder Woman's New 52 reboot.

9 SHAZAM VS. SUPERMAN

Superman fighting Shazam by Ed McGuiness

While Shazam and Superman are usually two of the friendliest heroes, the two characters haven't always gotten along. When C.C. Beck and Bill Parker created Shazam for Fawcett Comics in 1940, the hero was called Captain Marvel. After being given powers by the wizard Shazam, the young Billy Batson could transform into a Superman-esque adult hero. After a few years, Captain Marvel was an outstanding success who was even more popular than Superman.

In response to Captain Marvel's existence, DC sued Fawcett for essentially ripping off Superman. After a lengthy lawsuit, Fawcett settled with DC and stopped publishing Marvel's adventures in the 1950s. In 1972, DC began publishing Captain Marvel's adventures under the name "Shazam," since Marvel Comics trademarked the name in the intervening years.

8 MAXWELL LORD'S LAST LAUGH

Maxwell Lord with a devious grin

For newer DC fans, Maxwell Lord has always been a bad guy, but that wasn't always the case. In 1987's Justice League #1, Lord debuted as the benefactor behind a new Justice League. Throughout Keith Giffen, J.M. DeMatteis and Kevin Maguire's landmark Justice League International series, Lord developed moderate telepathic abilities during the team's light-hearted adventures.

Maxwell Lord took a serious turn in the lead-up to the 2005 crossover Infinite Crisis.

In Countdown to Infinite Crisis, Blue Beetle discovered that Lord had secretly been plotting against the League for years in a twist that received a mixed reception. After taking out his former friend, Lord released hundreds of superhero-hunting OMAC robots. Wonder Woman finished Lord off on live TV in the story's controversial conclusion.

7 WATCHMEN IN THE DC UNIVERSE

Doomsday Clock from DC Comics with Superman and Doctor Manhattan

While Before Watchman didn't sit well with a lot of fans, it was fairly easy to ignore since those comics existed in their own world. The same couldn't be said for DC's subsequent Watchmen plans, which inserted the characters into the heart of the DC Universe. In 2016's DC Universe: Rebirth #1, it was revealed that Watchmen's Doctor Manhattan initiated the New 52 "reboot" by erasing a decade of history from the DC Universe.

After Batman and the Flash investigated this theory in the 2017 crossover "The Button," several Watchmen characters traveled to the DC Universe in Geoff Johns and Gary Frank's ongoing series Doomsday Clock. Despite some early hesitation from some fans, all of these stories have received widespread critical praise.

6 SUPERMAN REVEALED

Superman Unmasked Lois Lane

Next to Romeo and Juliet, Superman and Lois Lane might have the most well-known relationship in fiction. Even though they always end up together, the couple still went through some rough patches over the years. After DC's New 52 reboot, their marriage was completely erased and the two were only friends. Naturally, that development didn't sit well with some fans, especially when Superman started dating Wonder Woman.

In 2015, Lois even did the unthinkable and revealed Superman's identity.

While the DC Universe learned that Clark Kent was Superman, fans were shocked by Lois' decision, even though she did it to keep Superman from being blackmailed. Shortly after that, the revelation was undone when these characters were overwritten by the married version of Lois and Clark.