WARNING: The following contains spoilers for "Dragonlance" from the Dark Nights: Death Metal Guidebook, by Christopher Priest, Eduardo Risso and Willie Schubert, on sale now.
One of the biggest surprise recruits in Batman's resistance against the Dark Knights and Batman Who Laughs in Dark Nights: Death Metal is the iconic Wild West gunslinger Jonah Hex. Risen from the grave as an undead warrior by the Caped Crusader's Black Lantern Power Ring, Hex has quickly proven to be a valuable ally against the Dark Multiverse invaders, showcasing his hardened survivalist skills as well as his heightened resilience from his zombified nature. And, in a short story revealing how Batman was able to recruit Hex into his insurgency, the scarred cowboy shows that he still hasn't missed a step as he takes down a literal dragon with a gallon of milk.
As Bruce Wayne approaches Hex with an offer to follow him to the Crypt of Heroes and help lead his undead army against the Batman Who Laughs, the two are pursued by a fire-breathing dragon bearing the face of the Joker as they navigate the rooftops of a post-apocalyptic Gotham City. As Hex tenuously agrees to Batman's request, he is visibly uncomfortable letting the dragon lay waste to the others that Batman has used the Black Lantern Ring to raise from the dead. Despite telling Hex to focus on the larger matter at hand and evade the dragon altogether, Hex decides to confront it head-on while giving it the respectful end it deserves.
Batman arms Hex with a gallon of milk and flash grenade while he provides support from the ground with a remote-controlled helicopter. As a skeptical Hex faces the dragon, the Caped Crusader provides the gunslinger with a crash course in chemistry and ornithology. Batman surmised that, like many birds, the dragon navigates its flight patterns by detecting Earth's magnetic fields. The protein enzymes found in common milk can be used to temporarily blind the dragon of its magnetic vision, coupled with the disorienting effects from the flash grenade. The gambit quickly pays off after Hex flings both items into the dragon's eyes, with Batman taking the opportunity to cut the monster's head in half with his helicopter's rotors.
The surprise showdown and quick ingenuity from the Dark Knight serves as a strong reminder that despite Bruce's many crimefighting titles, he is still the World's Greatest Detective, putting his knowledge of science to use with the random objects he has on hand. Hex's willingness to trust Batman with these seemingly unrelated items and insist on taking down the dragon before it can consume any more of the undead shows that death has not betrayed Hex's deeply held code of honor, both to his fellow soldiers and to the monstrous dragon by facing nobly rather than avoiding a fight to put it out of its misshapen misery.
At first glance, Batman and Jonah Hex don't appear to be the most logical pairing but, as Death Metal has continued, Hex has quickly become one of the Caped Crusader's most trusted allies in the fight against the Batman Who Laughs. Combining both heroes' steely determination, Batman's extensive scientific background and Hex's raw grit, the two characters slew a literal dragon in a battle that proved to Hex that Batman was a worthy enough companion to entrust his unlife with. And, as the war against the Darkest Knight and Perpetua escalates, this bond may be the very thing that saves the entire DC Universe.