Although Barbatos was the true big bad of Scott Snyder and Greg Capullo's Batman-centric DC Comics event Dark Nights: Metal, one could argue that the antagonist whose presence was felt the most over the course of the six-issue miniseries, as well as the various one-shots and tie-ins, was the Batman Who Laughs -- a version of the Caped Crusader with decidedly Joker-like tendencies. However, while his appearances since the conclusion of Metal have been few and far between, Snyder has since teased that the Batman Who Laughs could be poised for another standoff against his heroic counterpart in the near future.
During a Reddit AMA, a fan asked Snyder if there was anything the writer wishes he and Capullo had done differently during their five-year run on Batman during The New 52. "I've gotten the chance to do almost everything I've wanted to with Bruce," Snyder replied, "but I'm still doing a lot with him now, between the book with Greg for Black Label (which we just started!) and what happens in JL with him - a lot of what happened in Metal haunts him and comes back around... (and I love crowbars)[.]"
While Snyder doesn't outright refer to the Batman Who Laughs by name, his allusion to crowbars certainly lends credence to the sinister Dark Knight's impending return. Upon his introduction, the Batman Who Laughs was flanked by several similarly twisted versions of Robin, each of whom repeatedly chanted the word "Crow," prompting the Batman Who Laughs to reply, "Bar!" This, of course, is a reference to The Joker famously beating the Jason Todd iteration of Robin to near-death with a crowbar before subjecting him to a devastating explosion that took the young sidekick's life.
Given the character's immediate surge in popularity since his debut, it's no surprise that DC wouldn't want to keep the Batman Who Laughs shelved for too long. However, it remains to be seen if his recent cameo in James Tynion IV and Jim Lee's Immortal Men will help set the stage for whatever else Snyder has planned for him moving forward.