Over the decades, Warner Brothers has released a wide variety of movies based on comics. There have been plenty of grim and gritty takes on the heroes, while family friendly and downright cartoonish versions have made it to the big screen. While there have been plenty of successes, DC movies have also had plenty of missteps. Also, by making such stylized fare, even successful movies may have a short shelf life when audiences decide they no longer like that style. This has meant that there are just as many, if not more, abandoned DC movies and sequels that will never see the light of day. This means that many of the plot lines that writers and directors set up will never be resolved.

RELATED: 15 Marvel Movie Plots That Will Never Be Resolved

This is especially true now that the DC Extended Universe is off and running. All DC movies have to exist in the same world (or, maybe not, depending on which rumors are true that month). The point is, anything that came before the DCEU is off the table. Also, with such a shaky start, it's pretty clear that the studio has changed course on the DCEU a few times. This means that plot lines introduced in early films are likely abandoned to make way for the new direction of the universe.

15 SINESTRO'S YELLOW RING

green lantern film yellow sinestro

There was clearly a plan for future Green Lantern movies after the initial 2011 movie. Unfortunately, the film was neither well-received by critics nor performed very well at the box office. This meant no sequels, which is a shame because the first film ended with Mark Strong's Sinestro taking off his green ring and replacing it with a fear-based yellow one, followed by him giving the camera a sinister smirk.

In the comics, Sinestro is a fallen Green Lantern who eventually goes on to form his own Sinestro Corps. Since his first appearance in Green Lantern #7 (1961) by John Broome and Gil Kane, he's gone on to become one of Hal Jordan's most ruthless enemies. Unfortunately, Warner Brothers rebooted the DC movie series, including Green Lantern, meaning Sinestro's fate will never be known.

14 JOKER'S FATE

dark knight joker

Heath Ledger's iconic take on the Joker in The Dark Knight (2008) is one of the most memorable performances in any comic book movie. When Batman finally beats the villain towards the end of the movie, Joker delivers a speech where he compares himself to Batman and states that he believes the two men are destined to fight again and again. Clearly, there were future plans for the character.

It's not known what Christopher Nolan and his team had in mind for the Joker, but whatever they were, they were tragically cut short. After completing work on the film, Heath Ledger tragically died on January 22, 2008, months before The Dark Knight was even released. Nolan decided not to recast the role, and the Joker wasn't even referenced in the follow up, The Dark Knight Rises (2012).

13 SUPERMAN'S SON WILL NEVER RETURN

superman returns son

After successfully launching the X-Men film franchise, Bryan Singer jumped ship to reboot the classic Superman movies with Superman Returns (2006). After returning to Earth from a years-long journey through outer space, Clark Kent has to rebuild his life. A big part of this is dealing with the fact that Lois Lane had a baby while he was gone, and is engaged to the man she believes is the father. It's eventually revealed, however, that Superman is actually the young boy's father.

The confusing logistics of this situation aside, the child's identity is a major reveal for the film's finale. A sequel was initially planned, and even given a release date before the original even opened in theaters. Unfortunately, the movie didn't perform to studio expectations. Eventually, the sequel died and the franchise was rebooted with super-powered-son-free Man of Steel (2013).

12 WHO WAS IN THAT OPEN KRYPTONIAN POD?

Man of Steel Supergirl

While searching for information about his origins, Clark Kent discovers an ancient Kryptonian spaceship in Man of Steel (2013). An old scout ship, it's full of long dead Kryptonians who passed away while still cryogenically frozen. There is one open pod, however, that's clearly visible in the background, which suggests that at least one member of the crew was woken up from hypersleep.

Promotional material actually revealed that the pod was inhabited by Kara zor El in Man of Steel Prequel (2013) by David S. Goyer, Geoff Johns, Zack Snyder and Jerry Oordway. This prequel leaves her ultimate fate unrevealed, however, and may not even be canon. The sequel, Batman V Superman (2016) didn't reference this plot line, and with no Supergirl movie slated, it doesn't seem like it'll ever be mentioned again.

11 IS THE DEVIL DONE WITH CONSTANTINE?

Constantine Keanu Reeves

While the film Constantine (2005) may not have a lot in common with the comic book version, it's still not a terrible movie. Damned to go to hell when he dies, Constantine works as an exorcist hoping to garner favor in heaven. He's also been diagnosed with lung cancer, so his time is running out. During the film's finale, Constantine slits his wrists, knowing that Lucifer will come to collect his soul personally. Of course, doing this saved another woman from damnation, and the selfless act redeems Constantine's soul, and he begins to ascend into Heaven.

A furious Lucifer actually saves Constantine's life and cures his cancer, hoping that the man will screw up again and re-condemn himself to damnation. While Constantine's soul was saved, the film's domestic box office wasn't strong enough to save the sequel's chances. Constantine may appear in the DCEU, but it won't be this version.

10 WHAT'S COLEMAN REESE UP TO?

Dark Knight Coleman reese

One of the major subplots in The Dark Knight (2008) involves a Wayne Industry employee named Coleman Reese. After looking through the numbers, he discovers certain discrepancies, and after further research into Batman's tech, he figures out that Bruce Wayne is the dark knight. After trying (and failing) to Blackmail Lucius Fox, he attempts to go public with his knowledge on live television. This gets him targeted by the Joker, who promises to blow up a hospital if Coleman Reese isn't killed.

Luckily, Wayne saves Reese, which is where his story ends. There were rumors that Reese would return as the Riddler, especially because his name Mr. Reese sounds like the word "mysteries." He isn't seen or heard from after Wayne saves him, leaving his story dangling. Even if he decided to keep the secret, it's unlikely that all the city's villains forgot that he knew Batman's real name.

9 CATWOMAN'S NINTH LIFE

Batman returns catwoman

After discovering that her boss, Max Shreck, is planning to steal Gotham's power, Selina Kyle gets dropped out of a window in Batman Returns (1992). She's revived by cats and becomes Catwoman, targeting Max Shreck for revenge. By the end of the film, she kills Shreck but is seemingly caught in an explosion, leading Batman to believe that she's dead as well. The final shot of the film, however, reveals that she's still alive.

There were plans for a Catwoman spin-off, with Michelle Pfeiffer and director Tim Burton returning. Unfortunately, the project languished in development hell, and both Pfeiffer and Burton moved on. A Catwoman movie was released in 2004, but starred Halle Berry as a completely different character, leaving the fate of Selina Kyle up in the air.

8 AMANDA WALLER'S FAMILY

green lantern amanda waller

In an attempt to set up connections to a potential connected film universe, Green Lantern (2011) introduced Amanda Waller as a government scientist. Played by Angela Bassett, this version was a relatively minor character in the film, but her backstory was briefly touched upon. After being exposed to Parallax, Hector Hammond develops psychic powers. When Waller has him brought in for treatment and study, he touches her and sees her memories.

He learns that her family was gunned down and killed years earlier, although not many details are given. When Green Lantern wasn't the hit DC wanted it to be, it was dropped from their cinematic universe. A new version of Waller was introduced in Suicide Squad (2016), with no connection to the Green Lantern character. Whatever plans DC had for this version, her backstory was scrapped and will never be follow up on.

7 JOHN BLAKE'S CRIME FIGHTING CAREER

dark knight rises john blake

The introduction of John Blake in The Dark Knight Rises (2012) at first seemed like a random move. Having never appeared in the comics, Blake felt like a random character to focus so much of the movie on, especially when he just deduced Batman's secret identity out of nowhere. The final scenes of the film revealed that Blake was actually the film's version of Robin, and the final shot shows Blake entering the Bat-cave, having inherited all of Bruce's gadgets and crime fighting tools.

Considering that Blake was just a regular cop, without any special training, it's hard to imagine him following in Batman's footsteps. Of course, the Batman franchise was rebooted to be part of the DCEU with Batman V Superman (2016), leaving Blake's story forever untold.

6 THE OTHER TWO-FACE… NO, THE OTHER-OTHER TWO-FACE

Batman 1989 Harvey Dent

After being cast as Harvey Dent for Batman (1989), Billy Dee Williams expected the character to return in future sequels, eventually becoming the villain Two-Face. In fact, it's rumored that Catwoman's infamous taser kiss with Max Shreck in Batman Returns (1992) was originally planned for Dent and would be the event that disfigured half his face. Tim Burton decided to cut the character from the sequel, however, and he didn't appear at all.

When Batman Forever (1995) went into production, it was decided to take the series in a more kid-friendly direction. Major roles (including Batman) were recast, and Tommy Lee Jones was brought on to play Two-Face. This movie had little connection with the previous entries, and Jones' version of Dent is clearly not the same character that Williams portrayed (aside from the major physical differences, Jones' Dent was older and more theatrical in his behavior).

5 LANA LANG WORKS AT THE DAILY PLANET?

Lana Lang Superman III

Margot Kidder, who played Lois Lane in Superman (1978) and Superman II (1980), had a disagreement with the producers, resulting in Lane being written out of Superman III (1983). While Lois is on vacation, Clark returns to Smallville and reunites with an old classmate, Lana Lang, played by Annette O'Toole. In the comics, Lang was often portrayed as competing with Lois Lane for Superman's affections. Lois returns by the end of the film, but she finds Lang working at the Daily Planet and appears to be slightly jealous, setting up future conflict for the two characters.

In Superman IV: The Quest for Peace (1987), however, Lang is nowhere to be seen. Oddly, a new character named Lacy Warfield was introduced, who also competed for Clark's love. The series ended after that film, and this version of Lana Lang was never seen or heard from again.

4 ANDREA BEAUMONT'S RETURN TO VIGILANTISM

Batman TAS The Phantasm

In 1993, Warner Brothers released Batman: Mask of the Phantasm, a theatrical movie that was part of the "Batman: The Animated Series" continuity. It introduced an original character, Andrea Beaumont, who sought revenge against Gotham's underworld as the Phantasm. Unlike Batman, however, Beaumont had no problem killing her targets. To make matters worse, she and Bruce have a romantic history and almost got married at the start of Batman's career.

The film ends with Beaumont leaving Gotham, seemingly done with the Phantasm. While the film received good reviews, it bombed at the box office, and Beaumont didn't appear again on screen until an episode of Justice League Unlimited. Here, it was revealed that she briefly worked for Amanda Waller as the Phantasm. This was towards the end of that series' run, however, and what happened to the Beaumont after Mask of the Phantasm will never truly be known.

3 WHAT HAPPENED TO ZOD?

superman 2 general zod

In one of the the most triumphant scenes in comic book movies, Superman tricks the evil Zod into losing his powers during the finale of Superman 2 (1980). Zod, unaware he's lost his strength, commands Superman to kneel before him. Of course, Superman starts to kneel, but then grabs Zod and throws him into a pit in the Fortress of Solitude. While the villain has been defeated, it's never shown what happened next.

A deleted scene actually answers the question: Zod was arrested by the arctic police (there are multiple versions of the film -- one ending with Superman turning back time, returning Zod to the phantom zone). Unfortunately, alternate cuts and deleted scenes aren't canon, so Zod's fate is a mystery. Many people believe that the fall killed him, but this isn't definite and the deleted footage proves this wasn't the filmmakers' intention.

2 THE RIDDLER KNOWS BRUCE'S SECRET

Batman Forever riddler

The Riddler's plan in Batman Forever (1995) to steal Gotham's brainwaves may have seemed just a little bit ridiculous, but it yielded one amazing result: Riddler learned Batman's secret identity and shares this with his partner, Two-Face. During the final battle, however, Two-Face is killed. Riddler survives, along with the information.

He's last shown in Arkham ranting that he is Batman, suggesting that he's gone completely insane (of course, he is a genius and could just be putting on a show). Riddler was set to make an appearance in a third Schumacher film, but it's not clear in what capacity. Schumacher planned on using the Scarecrow, so Riddler might have just appeared as an illusion. Since he was still alive, however, it's possible that he might have appeared in person. The failure of Batman and Robin (1997) saw that the third Schumacher film never saw the light of day.

1 THERE WAS A SECRET DEMIGOD IN WONDER WOMAN

Wonder Woman chief napi

In one of the cooler scenes (out of many) in Wonder Woman (2017), Diana meets a native American named Chief Napi. Working as a smuggler overseas during World War I, he and Diana have a brief conversation in his native tongue (part of her training on Themyscira involved learning all the world's languages). This brief conversation wasn't subtitled, so most audience members didn't realize that Napi was revealing himself to be a Blackfoot demigod.

The actor himself explained that his character was actually meant to be a demigod, and that it wasn't just a fun bit of dialogue for fans to discover. While this helps make Wonder Woman a richer experience, it also opens many doors. Doors, it seems, that Warner Brothers doesn't seem to have any plans exploring any time soon. Eugene Brave Rock, the actor who played Napi, isn't currently confirmed for any future DCEU roles.

Do you know any other dropped DC movie plots? Let us know in the comments!