A new leak tied to LEGO Batman: Legacy of the Dark Knight may have revealed additional details about the game’s upcoming Mayhem Collection DLC ahead of its planned September 2026 release.
The information was shared online by X0XLEAK, who posted what appears to be a list of enemy factions and supporting characters connected to the expansion. According to the leak, the DLC will feature several members and affiliates linked to Task Force X, including Bronze Tiger, Captain Boomerang, Deadshot, Deathstroke, Javelin, Katana, Killer Croc, King Shark, Mongal, Polka Dot Man, Rick Flag, and A.R.G.U.S operatives. The list also mentions cops and “Ally Goons for Joker & Harley.”
One name included in the leak, “Lester,” is speculated to reference The Electrocutioner, though that detail remains unconfirmed.
Developed by TT Games and published by Warner Bros. Games, LEGO Batman: Legacy of the Dark Knight is an open-world action-adventure title built on Unreal Engine 5. The game follows Bruce Wayne’s rise from a young vigilante into Gotham City’s protector while featuring a large brick-built version of Gotham filled with combat encounters, collectibles, and references spanning multiple eras of Batman history.
The Mayhem Collection DLC was previously announced as a post-launch expansion focused on a large-scale Arkham Asylum breakout. Players will reportedly take control of The Joker and Harley Quinn during a new story mission set across Gotham City. Warner Bros. Games also confirmed that the expansion includes a new “Mayhem Mode” centered around villain-specific abilities, gadgets, and takedowns.
The DLC additionally comes with the “Sinister Pack,” which adds a new Batmobile, Batcave decorations, and seven villain-themed suits usable in the main campaign. The Mayhem Collection will be included for owners of the game’s Deluxe Edition.
