The following contains spoilers for Justice League: Warworld, now available on Digital, 4K Ultra HD and Blu-ray.
One of the unique aspects of Justice League: Warworld is how the concept of Warworld has been tweaked. In the comics and cartoons, it's usually depicted as a cosmic gladiator arena. Heroes and villains would be imprisoned and forced to fight each other -- something Justice League Unlimited brought to life. In Young Justice, it was even turned into a Death Star, leaning more its other purpose as a roving destroyer. This film changes things up a bit.
In Warworld, Mongul keeps prisoners, using a restrained Martian Manhunter to push nightmares into their minds. This allows the vessel to be fueled by negative energy, so it can roam and acquire new victims. Some of the current captives include DC's Trinity: Batman, Superman and Wonder Woman. In this case, Bruce Wayne envisions himself as a Conan-like Batman, not realizing he's a slave to Mongul's mental games. However, as much as Bruce has lost his identity, an obscure DC hero reminds him what it means to be a hero, which is quite timely, given the next war to come.
Warworld's Batman Is a Selfish Traitor
While the Warworld feeds off Wonder Woman being trapped in the Wild West and Superman investigating aliens, Bruce has a more dangerous nightmare. He's a brute stealing from tribes, and killing people and monsters to survive on Skartaris, which is essentially, DC's version of the Savage Land. Along the way, Bruce ends up meeting Warlord, who is leading a rebellion to free his people from the mage ruling over them: Deimos. However, rather than kill Bruce, Warlord finds use for the mercenary. Learning this stripped-down version of Bruce knows the way to Deimos' lair, he brokers a deal. Once Bruce can get them in to kill this supernatural oppressor, Skartaris can be free again.
Bruce has no choice but to enter this uneasy alliance, though the distrust is quite evident. While Warlord believes Bruce can make a U-turn and forge a better life with the rebels, Warlord's allies are quite cynical. Sadly, as they make the raid and try to infiltrate, most of Warlord's teammates get picked off. To make matters worse, Warlord's faith isn't repaid as Bruce betrays Warlord at the palace. It turns out Bruce was baiting them in, as he was sent as a spy by Deimos. Bruce's traitorous turn culminates in him trapping Warlord in a cage for a Minotaur to kill. This act cements Warworld's Bruce as one of the most selfish and hopeless iterations yet. However, as much he wants Deimos' gold as payment, Bruce thinks being Deimos' servant is the only way to live on Skartaris.
Warlord Shows Bruce Wayne the Truth - At a Price
It's worth noting Bruce's heel turn has to do with his grief. Despite teaming up with the Justice League in the Tomorrowverse, he's always had that lone wolf mentality. It showed a lot when he chided Superman for mentoring Supergirl in Legion of Super-Heroes. Unfortunately, this cynicism manifests in the most negative way when J'onn J'onnz taps into his past trauma. Bruce processed his parents' deaths in the worst way possible, creating a self-defense mechanism and mental reflex that now has him looking out for himself.
Luckily, Bruce realizes how sadistic Deimos is when he sees the villain torturing rebels. This appeals to the heroic nature that's been repressed. Coincidentally, a surviving Warlord intervenes and paves the way to defeating the sorcerer by saving everyone and affirming to Bruce they should always fight for what's right. Warlord even forgives Bruce, which is pivotal to sparking memories about his real life as Batman. With this bit of self-realization, Bruce finds a gateway to go back to his body for the Warworld ending. However, it's a tad cruel and doesn't offer up any good karma to Warlord.
While Warlord remembers his past on Earth as an SR-71 pilot named Travis Morgan, Martian Manhunter blows up the vessel to ensure no one can use it again. The Trinity survive, but head off for the upcoming Crisis on Infinite Earths. This gives Warlord the most tragic ending, because without Warlord inspiring Bruce, Batman wouldn't have broken free and helped stop Mongul. Still, as sympathetic as Warlord is, just like his comic book counterpart, he stands tall as a truly selfless freedom fighter in a wild world. This is something Bruce has taken forward for the next crisis to come.
Justice League: Warworld is now available on Digital, 4K Ultra HD and Blu-ray.