Kevin Conroy plays the Kingdom Come Batman in Arrowverse's Crisis on Infinite Earths crossover event, but this particular version of the Dark Knight isn't like the others people might expect. It's been known for several months now that Conroy had been cast in Crisis on Infinite Earths, but nothing had been said about what character he was playing.

It was presumed that Conroy would be playing some version of Batman or Bruce Wayne. This seemed a safe bet since Conroy is a prolific voice actor and is widely considered to be the definitive voice of Batman after decades of voicing the Caped Crusader in dozens of video games and animated series. This still left a lot of wiggle room regarding ideas as to which version of Batman he might appear as, with the most popular theory suggesting he would be playing a retired Bruce Wayne ala Batman Beyond.

Related: Arrowverse Theory: Crisis On Infinite Earths Will Create The Justice League

This speculation was rendered moot after photos were released showing Conroy wearing an armored exoskeleton similar in design to the one worn by Bruce Wayne in Kingdom Come. This prompted concept artist Andy Poon to confirm that Conroy was playing the Batman of the Kingdom Come reality, which is well known to classic comics fans but may be a whole new world for many fans of the Arrowverse.

Kingdom Come Explained

Kingdom Come art by Alex Ross

Kingdom Come was a four-issue miniseries, originally released in 1996. Written by Mark Waid with painted artwork by Alex Ross, the reception to Kingdom Come was almost eternally positive and its effect on the comic book industry was immediate and far-reaching. For many years, Kingdom Come was poised to become the official future of the DC Universe and its version of Superman made a guest appearance in the monthly JSA series. Today, the miniseries is still considered a classic of the Modern Age of American Comics and its reality has been designated Earth-22 in the post-Rebirth DC Comics Multiverse.

Set roughly 20 years in the future, Kingdom Come centers upon Norman McCay; a minister who starts having prophetic dreams about the end of the world being triggered by a war between the superheroes. This earns McCay the attentions of The Spectre; an angel of vengeance who has also seen the coming disaster and requires a human host to ensure that those responsible are punished. Through McCay's eyes, we see the build up to the war, which begins with Superman returning from a self-imposed exile following the death of Lois Lane and the acquittal of Magog, the hero who murdered the Joker after he had already been subdued and arrested by Superman. Forming a new Justice Battalion to replace the Justice League, Superman begins imprisoning all those superhumans who will not join his team and fight crime by his rules.

The war begins in earnest after a group of supervillains led by Lex Luthor and a group of rebellious heroes led by Batman enact a plan to kill Superman utilizing a brainwashed Shazam. Though Batman and his people were only working with the villains to figure out what Luthor was up to and sabotage his plans, they still fail to stop the brainwashed Billy Batson from being released as Superman and his forces are trying to stop a riot at their super-powered gulag. Ironically, Shazam turns out to be the key to victory, sacrificing himself to prematurely detonate the nuclear bombs dropped on the site of the gulag battle by the United Nations. This action still sees thousands of people dead but leaves Earth's population of metahumans at a more manageable level and inspires most of those assembled to work with the governments of Earth to find solutions to save the world that benefit both humans and metahumans.

Related: Arrowverse Is Fulfilling Crisis On Infinite Earths' Original Goal

Kingdom Come Batman Explained

Kingdom Come's take on Batman is perhaps the most famous older version of Bruce Wayne in all of comics' history, after Frank Miller's Dark Knight Returns. Beaten in body but not in spirit, time may have slowed this Batman down but it hasn't dulled his wits. If anything, old age has only made Bruce Wayne even more cunning and bolder than he was as a young man.

The second chapter of Kingdom Come reveals that Bruce Wayne still protects Gotham City, utilizing an army of robot Batmen that are able to quickly respond to even the most minor of crimes within seconds. This has made Gotham City a veritable paradise compared to most of the other large cities in the world of Kingdom Come, which are the frequent sites of battles between the various super-powered gangs, who fight one another over which territories they "protect." The grim irony of this Batman is that he seems to have finally won his war on crime, but he's lost everything else that mattered to him.

When Superman first approaches Batman to ask him about joining the Justice Battalion, he discovers that Bruce is only able to walk through means of a special exoskeleton, his body having suffered greatly over the course of the past two decades. He also learns that it is public knowledge that Bruce Wayne is Batman and that Bane and Two-Face burned Wayne Manor to the ground years earlier, though they never did find the entrance to the Batcave. It is also revealed that Bruce became estranged from his adopted son, Dick Grayson, and hadn't spoken to the former Robin in years.

The Kingdom Come Batman still resonates after all these years because of one scene, as the war is starting, in which Superman returns to the Batcave and pleads for his old friend to help him avert the coming disaster. Many comic fans believe this is a defining scene for both the characters of Superman and Batman across any medium, tying the World's Finest heroes together through their shared belief in the sanctity of life and their refusal to kill in the name of some greater good. “The deliberate taking of human - even superhuman - life goes against every belief I have - and that you have,” Superman tells Batman. “More than anyone in the world, when you scratch everything else away from Batman, you’re left with someone who doesn’t want to see anyone die.”

How Kingdom Come Batman Fits Into Crisis On Infinite Earths

Kingdom Come Batman flies into battle in DC Comics.

The original Crisis on Infinite Earths comics united the heroes of different realities and different time periods in a war to save the multiverse. Given that and the popularity of Kingdom Come over two decades after its original publication, there is ample reason to try and work it into the Crisis crossover event. It is also worth noting that Kingdom Come routinely tops the polls of classic comic book stories fans wanted to see adapted into full-length films.

Kevin Conroy's casting is also notable as this is the first time he has played Batman in a live-action production after decades of voicing the character. It will be interesting to see if Conroy can make the leap between being the voice and being the Bat, even if he is playing a version of Bruce Wayne that is more of a strategist and less of a front-line fighter. It will also be interesting seeing how Conroy plays against Brandon Routh, who is playing the Kingdom Come Superman.

Next: How The Arrowverse Will Look Different After Crisis On Infinite Earths