"Evil... as old as time, spreads like a plague, corrupting the hearts of men. For millennia, there have been those who have stood against it. A secret organization to protect mankind. They are the frontline in an unholy war. They are...the Darkwatch."
All There in the Manual: The Darkwatch has been fighting vampires and zombies since the days of the Roman Empire. Promotional material includes images of Darkwatch Regulators from all across history, including both World Wars and the present day.
Boring, but Practical: The Blackfish carbine, a powerful repeating rifle with a generous ammunition capacity. It's found at the beginning of the second mission and is common from then on. It can easily become a Sniper Rifle when combined with Vein-O-Vision, though it doesn't hit as hard as the actual Sniper Rifle.
Creepy Cool Crosses: Though the actual Darkwatch logo is a sheriff's star with a cow skull emblazoned over it, it usually appears only once on a given object (gun, piece of clothing, building, train, what have you). Every other available spot will be occupied by a stylized cross. The Blackfish carbine uses one as its hammer. Hell, it's in the logo!
Hellish Horse: Jericho's first (and only, if you're a nice guy) blood-suck victim is a horse, which then rises anew as his undead steed. It can be summoned and dismissed at will, and appears to feel no pain, as Jericho uses him to take cover from incoming fire during the horseback segments.
Hell on Earth: Deadfall, the town Lazarus uses as his base of operations, has turned into this, complete with lava flowing through part of the town.
Hangtown, earlier in the game, lacks the lava flows, but is still chock-full of the undead.
I Can Rule Alone: In the bad ending, Jericho bites Tala and drains her of her blood.
Injun Country: One or two levels. The zombified braves come at you with throwing axes and the like.
Karma Meter: Depending on if you choose the good or evil options at certain points, Jericho will either learn good spells or evil spells (and be yelled at by Cassidy).
Large Ham: Lazarus just loves to chew up the scenery. Lampshaded in the first chapter after the first fight against Lazarus by the subtitles reading "Triumphant laughter that swells to over-the-top laughter."
Nice Hat: Jericho wears a black-with-white-trim hat with a low crown and a very wide brim, resembling a priest's hat or quake hat. The Regulators all wear your standard ten-gallon hat—in black, of course.
Nice Job Breaking It, Hero: Chapter 2's opening text, "Nice going, outlaw. Your soul is slipping away, and Hell's own horsemen nip at your heels."
Stuff Blowing Up: Rocket launchers weren't exactly standard issue at the time, so what did the Darkwatch do? Stuff a bunch of explosives into a naval signal flare launcher! They added a studded maul to one end for good measure. More ordinarily, Jericho can throw sticks of lit dynamite at opponents. Used in one trailer to impressive effect. Oh, and the double-crossbow that shoots bolts with dynamite stuck on 'em.
Vein-O-Vision: Jericho can use his vampire sight to easily spot the undead.
Videogame Cruelty Potential: In Hangtown, the other agents are shooting everyone as a precaution to the undead uprising. You can come across a lone uninfected survivor in an alley who begs for you not to tell the other agents. Just as you get out of the alleyway, an agent comes up to you and asks if you found anybody. You can either tell him no and let the guy live, or tell them you saw someone and they go in and kill them. For added cruelty, you can say no (which Cassidy will praise you for), then go back into the alley and kill him yourself (and get chewed out by Cassidy).
Weaksauce Weakness: Although sunlight doesn't harm him directly, standing in it will drain Jericho's Blood Shield and prevent him from using any abilities, including his Double Jump. Invoked in Cartwright's test and in the level where you retrieve the Deadlight Prism (standing within its aura allows Jericho to use his powers).