Can't Take Criticism: Do not compare Raiden to Shao Kahn and/or Shinnok. He refuses to admit how much worse he is than both of them combined which many other characters are aware of. He will scream and zap you if you do.
Card-Carrying Villain: Raiden openly gloats about conquering Outworld, relishes bringing immense pain onto others (especially the Cage family) and wants to control all the realms so he could bring down Armageddon - and it's played very darkly straight.
Kano and his Black Dragon clan are quite open about their love for evil. Tasia even gives a speech about it to Kira.
Character Development: Raiden, though starting out as a Knight Templar and Well-Intentioned Extremist, is initially much more collected and methodical. But as the plot progresses, he becomes so angry and insane that he has no problems using violence and torture to fry the Lin Kuei to near-death, attack the Edenian Resistance, have Cassie Cage kidnapped and tortured, physically and psychologically abuse his ex-allies, orders the destruction of Li Mei's village, or use BlackMail and manipulation on several of his current allies.
The Chessmaster: Raiden, at least at first. As his insanity worsens, its hard to tell how in control he is.
Chronic Backstabbing Disorder: Not only are most of Raiden's lackeys (Shang Tsung, Noob Saibot, etc.) plotting to betray him — but also each other. Given that most of them are hypocrites, backstabbers and traitors (except for a Noble Demon like Daegon and a victim of Blackmail like Nitara) it's not a stretch to think they'll stick together; even Raiden intends to betray them, should they double-cross him.
Even though Shao Kahn was Reforged into a Minion, Mileena, Tanya and Baraka intend to free him by any means possible so they could go after Shang Tsung, Raiden and Hotaru.
Noob Saibot and Shang have formed a Deadly Alliance of some sorts, but both have intentions to betray each other.
Daegon and Kano don't get along with each other; the case is the same with Hotaru and Havik.
This is literally both Tanya and D'Vorah's defining trait, although in the latter's case it's at least somewhat justified by her beliefs in power equaling survival.
Goro decides to betray the Red Dragon Clan and join Shang Tsung and Noob Saibots alliance.
The Conqueror: Raiden intends to conquer Outworld and the Netherrealm in order to "keep" Earthrealm safe. Its stated more than once how similar hes become to Shao Kahn in this regard, he refuses to admit it.
Cold-Blooded Torture: How Kano, and later Raiden, torture Cassie after kidnapping her. They also do the same to Kevin.
Kevins mother and Kabals wife Nell was subjected this by Kano in addition to being raped many times for days because Kano wanted to get revenge on Kabal by turning her into a sex slave.
Raiden vs everyone, literally. He curbstomps everyone who opposes him throughout most of the story proper.
Triborg, at the S-F base.
Shang Tsung is on the receiving end of one in chapter 51.
Sonya and Fujin send Sindel to get Orin, who deals great damage to the Brotherhood of Shadows and forces Raiden to retreat from his attack on Kotal Kahn's palace while the emperor was away. This marks the heroes' first major victory over him.
Darkest Hour: The attempted invasion of Outworld by a corrupted Raiden has forced Kotal Kahn to ally with Liu Kang and Fujin in order to take him down and stop him from instigating Armageddon.
Dark and Troubled Past: Kevin. Loses his mother to a drunk driver, ran away from foster homes, tried to kill himself several times (either by overdosing himself or suicide by cop) before being found by Kano, who proceeds to torture him and try to make a mini-Me of himself.
Kira. Not only were her parents abusive, but they also sold her into sexual slavery when she was nine. She later got revenge by brutually murdering both her slaver and her parents.
Although Kira has since retired from this, she still looks the part.
Darker and Edgier: After his corruption, Raiden begins to use the same brutal tactics once used by Shao Kahn and Shinnok. But the tactics used by Shao Kahn or Shinnok pales in comparison to the savagery and sadism Raiden shows when it comes to silencing his former allies.
Death Is Cheap: Seems to be a recurring gag in the Mortal Kombat series - Shang Tsung not only revives himself, but also Mileena, Baraka, Mavado, Havik, Reiko, Kobra, Kia, Jataaka, Drahmin, and Moloch from the dead. Shao Kahn is Reforged into a Minion by the sorcerer. Shang Tsung even lampshades it.
Kira and Kabal also count as this due to their reasons for leaving the Black Dragon, the former snapping after witnessing the rape and torture of Kabal's widow Nell and the latter after looking into the eyes of a boy whose father he murdered right in front of him.
Sub-Zero and Frost also qualify as this, as they turn down Raiden's offer to destroy Outworld. Frost even declines Raiden's offer to seize control of the Lin Kuei from Sub-Zero. While Sub-Zero ended up in a coma, he reawakens from it in chapter 27.
In chapter 16, Ruby refused to tell Raiden where Rain was even though he threatened to make her watch as he killed all the Edenian refugees. Luckily, the revenants arrive in time to stop him.
Jade is this, as she did not want to be one of Quan Chi's lackeys, which lead to him killing her while forcing Kitana to watch.
Kevin also remains defiant even when being tortured by Raiden and Kano.
Kira and Kabal also count as this, as they realized what they were doing as Black Dragon members was wrong.
Scorpion defiantly defects from Raiden's side after witnessing Cassie and Kevin's torture too many times, and when the thunder god threatened to torture Jacqui and Takeda.
Raiden's ex-allies remain defiant even when he threatens to destroy them.
Despair Event Horizon: After her daughter is kidnapped by Raiden and Kano, Sonya is on the verge of losing her sanity, and desperately activates Triborg (though it doesn't end good, and almost ends up disastrous). Fortunately, the only thing that stops her from losing all hope is that she still trusts Johnny, who assures her that they'll get Cassie back in no time.
Delia and Taven experience after Raiden turns Daegon against them.
Li Mei goes through this when Raiden orders Hotaru to destroy her village.
To be fair, at that point, Cassie had been kidnapped, Sub-Zero was put into a coma and Earthrealm was pretty much willing to ally themselves with the Netherrealm. They were likely desperate at that point for someone to work with. Thankfully, she was smart enough to put a failsafe before Shang Tsung steals the data chip.
Scorpion pulling a HeelFace Turn when he realizes what could happen to his protege Takeda if he dares to defy Raiden, noticing how the thunder god brutally tortures Kevin and Cassie AND after realizing how he was being used as a tool by Raiden.
Shang Tsung coming Back from the Dead. Not only that, but he takes Triborg's data chip from Sonya. Thankfully, she was smart enough to put a failsafe.
Sub-Zero is on the receiving end of this from Smoke, who later drops it.
Li Mei refuses to snap out of it after her village is destroyed until Erron Black manages to convince her otherwise after she loses to Hotaru in the tournament.
Scorpion is on the receiving end from Sub-Zero, as he participated in the assault against the Lin Kuei, though Sub-Zero does forgive him.
Double Standard: Rape, Female on Female: Averted. Tasia groping Nell is portrayed as being no less disgusting and horrific than Nell's rape at Kano's hands, and the same applies to her attempt to rape and then maim Nell before Kira stops her.
This is also the case when Tasia reminds Kano and Jarek to share Jacqui with her because she wants to have fun with her too. Luckily for Jacqui, she wins their fight and humiliates Tasia, saving herself from this fate.
Downer Beginning: Kotal Kahn is forced to invoke Mortal Kombat in order to stop Raiden's invasion of his battered realm. Even some of Kotal Kahn's champions are injured, though Torr later slips into a coma (he suffered major electrical burns, incapacitating him); he later awakens from it in chapter 28.
The Dragon: Scorpion and Kano start off as Co-Dragons to Raiden. Of the two, Scorpion's a Noble Top Enforcer while Kano is in it for For the Evulz as well as Raiden's offer of a pardon. But after Raiden threatens to kill Takeda, Scorpion decides to defect and pull off a HeelFace Turn; he is subsequently replaced by Hotaru in chapter 24 as Raiden's right hand man. Kano's failure to stop Kira and Sonya from rescuing Cassie results in him being demoted to Evil Genius and replaced by Shang Tsung.
Dragon with an Agenda: Shang Tsung has his own agenda. Interrealm intrigue is like the game of thrones: you win or you die. And Raiden is so concerned with his former allies that he does not see Shang preparing to stab him in the back. Ironically, many on Raiden's side plan to back-stab each other, and even Raiden plans to backstab Shang Tsung.
Drowning My Sorrows: Jax even tried to kill himself after recovering, but Vera managed to talk him out of suicide.
Dude, Not Funny!: Chapter 63, where many of Raiden's ex-allies berate him again for toying around with their emotions, especially since he took advantage of Scorpion's guilt and made him his Number Two.
Easily Forgiven: Hanzo, surprisingly. It helped that Cassie vouched for him and he retold the confrontation with Raiden from his chapter.
The Elder Gods Must Be Lazy: Or as Liu says, the Elder Gods now fear Raiden more than Shinnok and Shao Kahn. Despite this, they refuse to help in the fight against Raiden.
At first, Liu Kang is the emperor of the Netherrealm. But this is eventually subverted for him after he's restored to life by Delia, and becomes The Atoner afterwards.
Noob Saibot becomes this in Chapter 61 when it's revealed that he faked his death, went into hiding for several years, and has taken over as emperor of the Netherrealm after Liu Kang and Kitana are revived.
The Empress: At first, Kitana's the empress of Netherrealm. But this is eventually subverted for her after she's restored to life by Delia, and becomes The Atoner afterwards.
Empathic Environment: In the 1st chapter, Kitana lampshades how the corrupted thunder god's appearance and presence unnerved her and Liu Kang (part of this is because he threatened to destroy the Netherrealm), and later on, is felt the same by Cassie Cage. The prologue even shows how he used his powers to block out the sun in Outworld, greatly weakening Kotal Kahn.
Emotion Control: Raiden uses Scoprion's guilt for killing Quan Chi (which resulted in Shinnok being unleashed and nearly dooms the revenants) to make Hanzo serve him. The former spectre turn against him after witnessing Cassie and Kevin being tortured too many times and because of Raiden threatening to target Takeda and Jacqui next.
Raiden takes advantage of Daegon's doubts and fears about being The Unfavorite to prevent him from rejoining his family. Daegon is showing signs of defiance, though, following Raiden's broken promise to Skarlet.
Enemy Mine: After Raiden invades his realm, Kotal must now seek an alliance with Liu Kang and Fujin in order to stop Raiden from inciting the same Armageddon he was once so desperate to stop.
For Raiden, he has Daegon and Kano fighting for him. The respective leaders of the Red and Black Dragons, of whose clans have a violent history with one another (as the Black Dragon split from the Red Dragon) are working together.
In Chapter 49, Dairou and Darrius agree to put aside their differences and form a temporary alliance with each other and with Fujin and Kotal Kahn in order to stop Raiden and Hotaru.
Scorpion steadily grows more disgusted with Raiden's brutality, his Cold-Blooded Torture of Cassie Cage and Kevin (Kano's son), when he realizes that Raiden was simply using him as a pawn (and when Raiden threatened to torture and kill Takeda and Jacqui) and how he uses outright violence in dealing problems, culminating in his sheer refusal to kill Fujin on Raiden's orders.
Sub-Zero and Frost say no to Raiden's offer to destroy Outworld, and despite being zapped to near-death, remain defiant.
Delia and Taven are willing to destroy Raiden after he manages to manipulate Daegon into his side.
Kotal Kahn, Reptile, Ermac, Erron Black, and Ferra/Torr are appalled that he would go so low to break Li Mei's will by ordering the destruction of her village.
Liu Kang, Kung Lao, Kai, Kitana, Jade, Smoke, Kabal, Stryker, Sindel and Nightwolf were already upset by Raiden's past actions, and the fact that he would go deeper into the abyss by kidnapping and torturing Cassie, mass-zapping the Lin Kuei and ordering the destruction of Li Mei's village.
Even Evil Has Loved Ones: Both Jarek and Tremor stop fighting to tend to Tasia after she loses both her hands. Even Kano is pissed, which distracts him long enough for Sonya to knock him out. They even console her later on.
When Taven calls his mother a whore, Rain punches him. Twice.
Daegon somewhat regrets killing his parents and still cares for his mother to an extent, the latter of which Raiden and Kano point out.
Skarlet is shown to be genuinely concerned about Daegon. Mavado shares her concerns.
It's surprisingly sweet to see how much Shao Kahn and Mileena care for each other. For all his anger at his betrayer, Shao Kahn is especially furious at those who betrayed his successor and Mileena in turns is upset by the disloyalty, indifference, and disrespect his other former enforcers display to him. She even calls him 'daddy' and promises to free him, which restores his hope in freedom and revenge.
Noob Saibot still cares about Sareena, albeit in a Yandere way.
Even Evil Has Standards: Daegon, despite being guilty of several crimes including murder, makes it clear that he is not a rapist like Kano.
Evil Former Friend: Raiden is this to Fujin, Jax, Johnny Cage, Liu Kang and many of his ex-allies that will choose to oppose his actions.
Evil Gloating: When Raiden announces his plans to invade Outworld, Fujin, Team S-F and the Lin Kuei are absolutely horrified at this. Later on, when Scorpion objects to Cassie's torture, not only does Kano tell-tale on him, but Raiden threatens to kill Takeda if Scorpion dares to defect. And when Cassie mocks him for what he did to her, he instead tortures Kevin, forcing her to grovel before him.
Raiden does the same thing in chapter 54.
Evil Mentor: Raiden is this to many of his former allies, especially Kung Lao, Liu Kang and Johnny Cage.
Raiden also serves as this to Daegon.
Kano tries to be this to Kevin but it's subverted as Kevin remains defiant against his father's will.
Evil Minions: Raiden has the Seidan army, the Black Dragon Clan, the Red Dragon Clan, the Tarkatan horde, and Brotherhood of Shadow as his stormtroopers.
The Thunder God takes bone-chilling and sadistic glee in torturing those who cross him; Fujin, Team S-F and the Lin Kuei realize this the hard way.
In a nutshell, Tasia's explanation to Kira on why she enjoys being the bad guy:
Tasia: The problem with you and Kabal, Kira, is that you both knew what you were doing while you were with us, you knew you were killing and torturing innocent people, you knew you were doing awful things. You just didn't think about it because you didn't want the guilt to make you hesitate. It wasn't until you saw for yourselves the truth of our work, how other people suffered and died because of what we do, then you realized you'd been lying to yourselves this whole time. And that's the difference between the two of you and the rest of us; you see, we knew the whole time what we were doing and the consequences or our actions might be, we knew other people paid the price because of us, we never lied to ourselves to make things easier and do you want to know why? Because we just don't care. That's the best thing about being a psychopath; we understand concepts like mercy, love and remose, but we don't experience them as emotions. And that, my dear Kira, is why everything we do is so damn easy!
Goro also feels this when he eliminated Sheeva's champions in chapter 28.
Hotaru also has shades of this, especially when he destroys Li Mei's village (on the orders of Raiden) in order to break her.
He also believes that Scorpion defected from him because of a lack of willpower, but it was actually his own ruthlessness and extremism that the former revenant to lose faith in him. The dark god's threat to have Takeda tortured if he defects was the breaking point for Hanzo, who was already dissatisfied with Raiden's brutality, especially when the evil god zapped the Lin Kuei to near death.
He also thought that Cassie's torture and what he did to the Lin Kuei would keep his former allies in line, but he didn't realize that this would only increase their resolve to destroy him.
Evil Counterpart: Raiden serves as this to Fujin. Both are Physical Gods of Earthrealm, but have differing goals on protecting it. Raiden wants to merge all the realms to "protect" Earthrealm, while Fujin is working with Kotal Kahn to stop the thunder god from instigating Armageddon. Raiden also serves as this to Kotal Kahn.
Skarlet is this too, as her flirtatious interactions with Daegon show.
Evil Has a Bad Sense of Humor: When Raiden, Shang Tsung and Hotaru mock at how Shao Kahn was Reforged into a Minion, Scorpion berates the thunder god for toying around with the emotions of others, including Daegon and Nitara. In general, Raiden often mocks at his enemies' plight.