The Mortal Kombat games aren't only gruesome and gritty in their gameplay, they also have very serious and often time extremely dark stories which help separate this franchise from other popular fighting games which tend to have a much more lighthearted tone.
This also means that the world of Mortal Kombat is full of despicable characters who have committed some heinous acts in order to become who we know them as today. While some of these characters become this way due to a harrowing backstory, others simply enjoy the act of killing their enemies in cold blood, making for an incredibly unique cast of fighters.
While the series entered its second timeline with the release of Mortal Kombat 9, many of the returning characters have still retained similar characteristics and backstories which have made them just as gruesome as they were before, or in some cases, even more frightening.
10 Scorpion
Despite being portrayed in a much more heroic light in recent Mortal Kombat games, it's undeniable that Scorpion has still committed some ruthless and downright disturbing acts throughout the series. After he and his clan are completely annihilated by the Lin Kuei clan, Scorpion comes back as a hell-spawned Spectre whose sole mission becomes hunting down those who killed him, his family, and his friends.
Not only does this underlying rage lead him to murder Sub-Zero in the first tournament, but Scorpion also tracks down Quan Chi whom he tortures mercilessly, with these two being just a few examples of characters who have become victims of Scorpion's unrelenting wrath. As the games have gone on, and Scorpion has learned the truth about the massacre of his clan, he has become slightly more honorable as a character, but that underlying rage can still lash out every so often.
9 Reptile
Reptile is literally the embodiment of the saying "don't judge a book by its cover" since while he may look dangerous and potentially evil, he actually has a tragic past that demonstrates just how dark the Mortal Kombat universe really is.
When a battle between the gods shook Earthrealm to its core, Reptile's species, the Saurians, escaped to another realm entirely, but it wasn't long until the warmongering Outworld emperor Shao Kahn decided to exterminate all Saurians from this realm in order to make it his own, leaving behind only a few to be kept as slaves. As Reptile watched his species be wiped out by the tyrannical emperor, he himself was taken in as a servant to Shang Tsung where he would be manipulated to only serve his new master.
8 Skarlet
Upon finding her living off scraps in the streets of Outworld, Shao Khan decided to take a young Skarlet under his wing, experimenting on her with sorcery and making her a master in the art of Blood Magik, something that would cause her to become fixated on making her enemies bleed, leading to some of the most gruesome fatalities in the series.
Skarlet even reveals to Shao Khan that her favorite blood is that which comes from Edenians which includes Kitana, her arch nemesis whom she sees as being a privileged but unworthy "daughter" of Shao Khan.
7 Noob Saibot
When Sub Zero is killed by Scorpion at the end of the first Mortal Kombat tournament, he is soon after resurrected by the mysterious sorcerer Quan Chi who had turned the once honorable warrior into the embodiment of evil by stripping him of all his good virtues.
This new Sub Zero, now known as Noob Saibot, became a nightmarish and maniacal monster who not only resides in the depths of the Netherrealm, but also wishes to one day rule over it, and while he will occasionally make factions with powerful enemies like Shinnok, Noob only looks out for himself after losing everything that made him good.
6 Cyrax
Despite being fiercely opposed to the mechanization of the Lin Kuei clan, Cyrax was forced against his will to become a coldhearted, obedient machine whose only task was to hunt down Sub Zero. While he does eventually regain his human soul with help from Sonya and Jax, many of Cyrax's quotes show him as a haunted shell of a man who ultimately is terrified of what he has become.
The dark reality of Cyrax's situation really becomes apparent in Mortal Kombat 11 when talking to Sub Zero who claims that they could find a way to restore him potentially from a different universe, only for Cyrax to respond "Please, don't bring me back as a machine. I can't live like this".
5 Mileena
Fearing that one day Kitana would betray him and take over his armies, Shao Khan decided to create a mutant hybrid clone who was designed to be the exact opposite of her counterpart, being a selfish, savage, and frightening warrior known as Mileena.
Being fused with a mixture of Tarkatan and Edenian DNA has not only distorted parts of Mileena's body, but it has also granted her an insatiable desire for killing, having no remorse for anyone who falls victim to her duel sai blades. She will also use her gigantic teeth to rip the flesh off her enemies, usually leaving behind only a pile of bones, with her final goal being to hunt down and kill her "sister" Kitana.
4 Kano
Many of the darker characters in the Mortal Kombat universe often have a tragic backstory that helps explain why they become the people they turn into, but when it comes to Kano, he is simply just a psychopath who loves nothing more than money, and seeing each realm burn to the ground.
Proving his ruthfulness as a Black Dragon, Kano's lust for killing and his opportunistic nature eventually saw him become the leader of the Outworld armies, making him an incredibly threatening figure in the lore. Additionally, players only need to see Kano's fighting style to see how merciless he is, often using knives to slice up his opponents before urinating on them to end off a match.
3 Shang Tsung
As the right-hand man of Shao Khan, it's no surprise that Shang Tsung is an extremely vicious character, but when taking into account that the shape-shifting sorcerer must consume souls in order to stay alive, it's easy to imagine just how ruthless of a person he really is.
Depsite the Elder Gods stating that Shang Tsung should only consume souls after battle, he has been shown on numerous occasions to do it for fun, with the hope that one day he will grow strong enough to betray Shao Khan and enslave all the realms to fuel his power. His monstrous Flesh Pit experiments have also resulted in creating some of the most hideous characters in the series such as Meat and Mileena.
2 Quan Chi
Everything Quan Chi has done during his appearances in the games has been for his own gain, with him being the reason for many of the mass killings and wars that break out throughout the series. For example, Quan Chi was the one who tricked Scorpion into thinking that it was the Lin Kuei who killed his clan, before then resurrecting Scorpion to be his slave.
He also brought Sub Zero back as the evil Noob Saibot, manipulated Shao Khan into commiting an act of genocide on Earthrealm, and in Baraka's ending in Mortal Kombat Gold, he commits omnicide just to rule over all the realms, even with nobody in them.
1 Shao Khan
Shao Khan uses his God-like strength and extreme brutality to intimidate realms into bending to his will, with his tyrannical rule of Outworld seeing him publicly execute anyone who shows any kind of resistance to his reign, with the only survivors being those who he can turn into malicious killers like Reptile and Skarlet.
During his multiple invasions, Shao Khan has enslaved the peace-loving Edenians, forced his wife Sindell to take her own life, stole the souls of the entire population of Earth, and even driven himself insane after having nothing else to conquer at the end of Mortal Kombat: Armageddon. He is truly one of the most despicable villains in gaming history and a terrifying figure both in the lore, and as an in-game boss too.
Mortal Kombat 1 releases on September 19 for Nintendo Switch, PC, PlayStation 5, and Xbox Series X/S.