Without looking it up first, I suspected this movie was based on a comic or graphic novel (it was). It seemed to contain a lot of visual motifs comic readers love like demons, religious figures, fire, portals to hell, bad behaviour, profanity, violence and sex.

It's fun enough but I hope the source material is a bit clearer about sketching out the mythology. As far as I could figure, a small cadre of ordained Catholics specialise in dispatching demons back to hell when they invade human hosts. That part's simple enough, but it seems that to do so they need to sin as much as possible so they can actually go to hell to escort the various demons back there when it's their turn to make the ultimate sacrifice (of their life).

That results in a fairly strong idea of hard-drinking priests who all smoke, swear gruffly, try to bang each other and record it all in a ledger, only for their nerdy manager-type member to admonish them when their numbers are slipping. Not only is bad behaviour a job requirement, it's surprisingly hard to excel at – it's just one of the great ideas here that's never fully realised, not portrayed on screen as clearly that it needs to be.

They're led by a perfectly cast Clancy Brown as Angus, the constantly prickly leader of the order who sprinkles creative swearing throughout every grizzled edict. When he and offsider Lawrence (Clifton Collins Jr) attend what they think is a routine exorcism, the Rabbi taken over by the demon warns them a more powerful foe than they've ever faced is coming, an ancient Norse demon named Surtr.

Later, teammates Elizabeth (Robyn Rikoon) and Macon (Macon Blair) try to dislodge an entity that's been living inside a guy who's been chained in a Fred Krueger-like basement for most of his life, a creature who turns out to be Surtr himself. When he's able to leap from his current victim to Elizabeth, she fails to commit the required act of suicide to drag Surtr with her to hell and wanders off, possessed by the most powerful demon who's ever threatened Earth.

Just when the Catholic church get wind of Angus and his underlings' blasphemous ways and shut him down, things reach their darkest point and the gang have to rally to do battle with Surtr at a swirling portal of fire in the shape of a huge vulva on an island in New Jersey, from which he's going to unleash all the forces of hell upon Earth.

There are some funny moments and lines thanks to the players (Dan Folger as the terminally unfussed slacker of the group is a standout), but the whole thing feels too self-consciously like it's aiming for cult status right out of the gate without having a distinctive enough story – the world it exists in is much more interesting and has much more potential.