The filmmakers Singer and McQuarrie deny that this is a supernatural thriller, claiming it’s simply the silly Hollywood movie it initially seems to be, but repeated viewings reveal its true nature as something more. The narrative focuses on five criminals who believe themselves to be deities, which offers an early indication of its supernatural elements. One of them, Keaton—portrayed by Gabriel Byrne, someone resembling Judd Hirsch—along with his attorney girlfriend, is involved in a transaction at an upscale restaurant with several other individuals. After watching it multiple times, you’ll notice that these people are not who they appear to be, as the lawyer is later shown entering into a bargain with a demonic figure. This "devil" is referred to by the five men as “Kaiser.” The connection to Caesar—the origin of the name “kaiser”—is a biblical reference to an otherworldly evil. You’ll discover the identity of this devil when you understand that, according to religious texts, he cannot speak truthfully; therefore, everything he says is false. These five criminals all aspire to be "better devils." One of them secretly represents the female lawyer, and the reason for this becomes clear upon viewing the film.

Source on TMDB