Zack Snyder's Justice League is coming to HBO Max next year as a four-hour special, and Snyder fans are agog with excitement speculating over what new material will be added to the film. Recently, a Vero account user posted a theory regarding the fate of Robin in the informally dubbed "Snyderverse" of DCEU movies. Later Snyder himself liked the post, prompting fans to believe that the theory will turn out to be true. You can read the entire theory below, which was reposted to Twitter.
"If Zack and David stick with the story of having Joker brutally beat Robin to death, then set his body on fire, then there's no doubt in my mind that it happened in Wayne Manor and the fire is what left the house looking like that. Another thing to think about with this if true is that Joker probably knows Batman's true identity but chooses to keep it a secret as he doesn't want his twisted back and forth relationship with Batsy to end."
In Batman v. Superman, one particular scene in the Batcave showed the Robin costume kept in a glass case. The costume had been heavily damaged, and the words "Ha Ha Ha" were spray-painted over it. This confirmed that the Joker had been responsible for killing Robin, mirroring the events of the comics where Joker beat Jason Todd to death with a crowbar when the latter had taken on the mantle of Robin.
Later, that theory was further confirmed in 2016's Suicide Squad, where it was stated that Harley Quinn had helped Joker kill Robin. The movie's director David Ayer had also stated that it was the death of Robin that had caused Batman to knock Joker's teeth out, forcing the Clown Prince of Crime to wear a metal grill in his mouth, and tattoo the word "damaged" on his forehead. Meanwhile, Snyder himself had previously revealed the impact that the death of Robin at the hands of Joker had on Batman.
"In my mind, it was that Robin had died 10 years earlier, during some run-in with a young Joker. So there was a fun backstory there to play with. I felt like the whole idea was that there had been loss and there had been sacrifice. In a weird way, [Bruce Wayne] had sacrificed everything to be Batman. He doesn't really have a life outside the cave. I thought that including Robin, a dead Robin, was helping us understand that he's been on quite a little journey."
Justice League features an ensemble cast consisting of Ben Affleck as Batman, Gal Gadot as Wonder Woman, Henry Cavill as Superman, Amy Adams as Lois Lane, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, Jeremy Irons as Alfred Pennyworth, Diane Lane as Martha Kent, Ciarán Hinds as Steppenwolf, Jesse Eisenberg as Lex Luthor and J.K. Simmons as Commissioner Gordon. Zack Snyder's Justice League will feature the same returning cast, with newcomer Ray Porter voicing Darkseid. The film will premiere exclusively on HBO Max in 2021.