WB Games Montreal has worked on this project but it is now believed that the new game is inspired by the series The Court of Owls.
WB Games Montreal worked on a game of Batman and some images of concept art have been leaked on 4chan, revealing locations and characters, among them Two-Sided, White Rabbit, Dick Grayson (Nightwing), Poison Ivy, Gorilla Grodd, and Black Mask.
however, this title cancelled provisional name Project Sabbath would not be a direct continuation of the Batman Arkham: would have been starred by Damian Wayne, who would face enemies classic Batman in a alternate version.
In one of the scenes we see Damian on a motorcycle and in another los buildings of Gotham with the tower Wayne in ruins.
The reason for the cancellation is not clear, but it is thought that was converted into a title that continues the saga Court of Owls and would allow us to traverse a Gotham of large dimensions. Could launch in October or November, with the announcement at Gamescom next week.