While almost certainly incidental, it's still worth noting that Dante Lam's That Demon Within ends how Drug War begins, with an out-of-control vehicle wreaking spectacular havoc. Both films tread similar genre terrain, but among the many differences between them, most striking is that, not only did Johnny To's film do substantially more with far less, but it gave real weight to the inner lives of its characters, and in the process earned its substantial body count.
That Demon Within stars Daniel Wu as Dave Wong, an honest cop, albeit one who's psychologically scarred past has limited his career options, and whose present unraveling compounds the toxicity of an unfolding situation involving stolen diamonds and a police informant. In its first half, the film suggests something enigmatic, even impressionistic, though it's telling that the use of lens filters brings to mind an obsessively stylized Instagram feed. For every visual trick that leaves a tangible emotional or psychological impression (the silent-film-like use of an iris effect to evoke burgeoning anger is especially noteworthy, if only for its simplicity), a dozen more feel arbitrary at best, and when this magician's bag of tricks runs out, it becomes clear they weren't adding up to anything in the first place.
What remains, then, are the kind of psychological shorthands that would make Charlie Kaufman sneer, a rolodex of arbitrary cinematic quotations (everything from Spike Lee's dolly shots and The Godfather's horse-head scene to the wailings of Goblin's work from Suspiria), and violence as thematically slight as it is morally callous. The cumulatively noxious effect is only heightened for wasting Wu's acutely felt performance, which, in its focus on internalized trauma, suggests the calm center of a monstrous storm, the suggested energy levels of which the surrounding film can only hope to match. Both portentous and weightless, That Demon Within rarely feels like anything more than an effort to pander to the kind of audiences that enjoy Quentin Tarantino's films for all the wrong reasons.