Matt Reeves has said that one specific comic served as inspiration for his approach to The Batman. The director held a panel during the DC FanDome event, where he said that Darwyn Cooke's Batman: Ego let him get into Bruce Wayne's mind.
"Because I wanted to get into the mindset of the character and I wanted to think of the psychology -- for me, I think one of the cool deep dive ones was Darwyn Cooke's Ego," Reeves said. "He's confronting the beast that is Batman. There's a kind of duality."
Reeves also said that the graphic novel dealt with Batman's "shadow side", which he also wanted to explore in the film. "So while he's doing all of these things for the reasons that he thinks is right and that have a heroic sort of grounding in them, there's also many things that are driven by the parts of himself he doesn't yet know. So I would say that that psychological union shadow side, that sort of version of it, is very much connected to that vision from Darwin Cooke, from Ego."
Ego dealt with Batman's insecurities, portraying Bruce Wayne and Batman as two separate entities struggling to co-exist. Cooke is well known for his DC Comics work, particularly The New Frontier miniseries.
The Batman is directed by Matt Reeves and co-written by Reeves and Mattson Tomlin. The film stars Robert Pattinson as Bruce Wayne/Batman, Andy Serkis as Alfred Pennyworth, Jeffrey Wright as James Gordon, Zoë Kravitz as Selina Kyle/Catwoman, Colin Farrell as Oswald Cobblepot/The Penguin, Paul Dano as Edward Nashton/The Riddler, John Turturro as Carmine Falcone and Peter Sarsgaard as District Attorney Gil Colson. The Batman is set to be released in theaters on Oct. 1, 2021.