Blue and Orange Morality: A hyper-exaggerated version of the mafia code. Jackie is okay with murdering anyone involved in organized crime by the hundreds, dealing drugs, prostitution, and collateral damage. However, if he kills a civilian he gets really disturbed by it.
Deconstructed with the fact Jackie tries to make Jenny's sister and later, a rebel woman into his Morality Pet. He turns decides against it when he realizes it would only expose them to needless danger and/or corrupt them.
Sarah Pezzini and their daughter, Hope, in a bizarre way.
Necessarily Evil: In the game, quite a few of the less-than-pleasant things that Jackie does is to ensure the safety of his allies; Johnny Powell certainly concurs with this belief.
Cloudcuckoolander: In the game, its dialogue swings from eccentric to downright weird; at one point, it even lurches into Buffy Speak by informing Jackie that it fixed his "broken head ball." However, it sobers very rapidly when it feels like making a point- or when its existence is threatened.
Clingy MacGuffin: The Big Bad of the Artifacts crossover said that it's almost impossible to separate The Darkness from it's wielder and The Darkness claims that not even death can take away it's host.
Gambit Roulette: The reason for the Darkness choosing the Estacado bloodline? They hoped, eventually, they would have sex with Darkness-created concubines enough that a child would be produced.
The Darkness may have just been taunting Jackie.
God Is Evil: The Darkness may well be as close to God as anything in the setting, along with The Angelus.
Though the second game mentions God as a separate entity on multiple occasions. For instance, the origin of the universe as explained by Johnny:
Johnny Powell: In the beginning there wasn't shit. Literally! Nothing but void and darkness, and that's how the Darkness liked it. It wasn't until God decreed that: "Turn on the lights!", that things got nasty.
Adaptation Distillation: The Brotherhood in the second game is much more menacing and powerful than the one in the comics.
Composite Character: There's a similar Evil Army version of the Brotherhood in the comic, it just worships the Angelus. Becomes Fridge Brilliance when you realize the Brotherhood has tried to use the Angelus in the games as well.
Deader than Dead: The only sane member of the Brotherhood has his soul destroyed by the Angelus for freeing the Darkness after they capture it. Johnny says this is the only time in history it's happened and is a poor reward for saving the world.
Go Mad from the Revelation: In the game it's implied the Darkness slowly drove them mad when they managed to capture it. The first time.
Xanatos Gambit: The cult in the game attempts to determine whether Jackie is the Darkness' wielder by sending an army of goons to kill him. If he doesn't, he dies, but if he does, they can get it from him.
Kick the Dog: A lot of what he does over the course of the game, like blowing up the orphanage that Jackie grew up in and most notably, killing Jenny.
Large Ham: Paulie never stops shouting. He is always angry.
It's All About Me: In the game, after he's called a hit on Jackie and tried to kill him with an explosive-rigged closet, he's inexplicably offended when Jackie retaliates by launching attacks on Paulie's various businesses.
Smug Snake: By and large, his comics incarnation is this; the game version's too grouchy to be even remotely smug.
Villainous Breakdown: When Jackie has him on the ground near the end of the first game, he starts begging with Jackie to spare him. However, this turns out to be a subversion, as it is a way to distract him so that he can grab for the nearest gun and kill Jackie.
Dangerously Genre Savvy: Even more so than Paulie; rather than just setting up some floodlights in front of his lair, he ambushes Jackie with several dozen spotlights and knocks him out with a flashbang. Then, while he's torturing Jackie, he keeps him under the beam of a floodlight at all times.
God Is Evil: The Angelus may well be as close to God as anything in the setting, along with The Darkness.
Grand Theft Me: The Angelus takes complete control over its host mind and body(e.g. Lauren Franchetti, Celestine Wright, and in game Darkness II Jenny), until its Heel-Face Turn after which its lets its host keep control over their mind and body.
Heel-Face Turn: After taking Danielle Baptiste as its host The Angelus as been on the side of good.
Ineffectual Sympathetic Villain: Deconstructed. Sonatine has nowhere near Jackie's level of power and often engages in quirky bizarre behavior, then he does something from behind the scenes that ruins people's lives.
Evil Cripple: He's hunchbacked, wears braces on his legs, and walks with the aid of a cane.
Evil Sorcerer: His knowledge of magical artefacts and supernatural powers put him squarely in this category; doubly so when he manages to capture the Darkness.
Faux Affably Evil: Brother Victor can swing from insulting to condescendingly polite at the drop of a hat, all the while insisting that he's doing what he does for Jackie's own good; under this exterior, Victor is as sadistic and monstrous as they come.
Flash Step: His powers allow him to move in this manner, handily overcoming his disabilities in the process.
Crazy Homeless People: According to Vinnie, the "new guys" found him living under a bridge in a cardboard box. They didn't (seeing as finding him is a goal of the first mission of the "Vendettas" campaign), but he does say that he lives in such a situation.
Crazy Sane: Johnny comes off as a complete nut, and he is but he's arguably the most well-informed man on the planet regarding the supernatural.
Nightmare Fetishist: If he's not terrified out of his life by it, chances are that Johnny will be gushing over a lot of the Darkness relics that are brought to him. The multiplayer campaign features him being alternatively fascinated and horrified by the four character's weaponry, noting the history or the magical power behind it- and frequently asking why anyone would bother using it.
Only Sane Man: As the only character in the entire game with adequate knowledge as to what might be going on, this is a given- even if he spends most of the game talking to himself. The Asylum levels take this even further, in which he's one of the few patients that can help Jackie escape.
Nice Guy: Compared to his colleagues at least and provided you're on his good side. Whenever he talks to Vinnie or Johnny on the radio he is always polite and seems happy to have found a follow scholar of the Darkness in Johnny.
Hollywood Voodoo: Some of his abilities seem to be channelling voodoo imagery. For bonus points, the achivement unlocked after completing a mission with him is called "Voodoo is more than dolls." He is also stated to have turned to a form of Louisiana Voodoo in an attempt to help his patients.
Animal Motifs: Dogs. A lot of his combat chatter has him referring to himself as "The Hound". Taken to extreme however when he actually starts howling like one.
The Atoner: Part of a bloodline of one. His sword Kusanagi was once used in the slaughter of one thousand innocent souls and a such each new bearer of the sword is cursed to feed it one thousand wicked souls to redeem it. The big catch however, is that for each day Kusanagi goes with out feeding, the bearer loses one year of their life.
Axe Crazy: A combination of his desire for revenge against the Brotherhood, along with his desire to feed Kusanagi's bloodlust has made him the most unhinged of the multiplayer characters.