With anticipation for Batman/Superman growing, Joshua Williamson sat down with CBR to talk about the upcoming series. Williamson explained Batman's influence on the comic's storyline, as well as why the decision was ultimately made to give the Dark Knight top billing over Supes.

In the beginning, Williamson focused on Superman for the new series. "There was a moment early on when it was going to be Superman/Batman, and it was going to be very Superman centric," he said.

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Williamson's focus shifted thanks to The Batman Who Laughs. "I think we started to switch it around when we realized that The Batman Who Laughs was going to be the underlying villain of it – because he's not the forefront villain, but he's has a presence in the book," he shared. "Once we knew that was going to be continuing from The Batman Who Laughs series and [Dark Nights:] Metal, then it changed to Batman/Superman – once we knew it was going to be a little bit more of his mythology moving forward."

Williamson also spoke about how Batman and Superman's relationship draws The Batman Who Laughs from his universe into theirs. "Even though, it's a lot about Superman. It's a lot about the relationship that Superman and Batman have," he shared.

"You know in the Dark Multiverse – this isn't a spoiler; this happened in Metal – they showed in The Batman Who Laughs special that the Batman Who Laughs killed the Superman of his world, and I think there's a part of him that regrets it," Williamson continued. "He came over with all these fake Batmen – all these Dark Knights – and they lost. And the Batman Who Laughs is like, 'I shouldn't have done that. I should have brought my Superman with me.'"

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The latest team-up between the Dark Knight and Man of Steel sees the two trying to find who amongst the DC universe's finest has the Batman Who Laughs infected.

Written by Joshua Williamson and illustrated by David Marquez, Batman/Superman #1 goes on sale Aug. 28 from DC Comics.