|“||You...will not see the end of this day!||”|
The story takes place after the events of Mortal Kombat: Armageddon, but during the time of the first three games: Mortal Kombat, Mortal Kombat II, and Mortal Kombat 3. The events of the games, however, take place in a different scenario because Raiden, the god of thunder, has knowledge of the future.
Mortal Kombat 9 is the first M-rated Mortal Kombat game to be developed for the seventh generation of consoles, as opposed to the T-rated Mortal Kombat vs. DC Universe. This is also the first title to include 3D graphics, although gameplay has been brought back to its classic 2D plane. The developers have also stated that this is the first game in which they are making a conscious effort to create deeper gameplay for more hardcore players.
The story begins with Raiden, just when he is about to be killed by Shao Kahn in the events that happen after Armageddon. In a last-ditch effort, he sends a message to himself in the past, in the era of "Mortal Kombat" (the first game). The rest of the story follows that Raiden's past and shows him trying to understand the visions and messages he gets from himself in the future and trying to prevent the events that lead towards the destruction of all realities, thus trying to change the course of history itself.
The player has the ability to play as multiple characters during the course of story. According to the developers, the story is longer than the story present in Mortal Kombat vs. DC Universe. The developers have noticed that the story had been ignored in the past in favor for the fighting gameplay, "action," and wanted to make a change in that for Mortal Kombat.
Excluded from the story campaign, players would be able to play as Kratos, God of War, who has his own personal set of moves, fighting arena with Stage Fatalities and his own personal story for Arcade Ladder mode.
|“||Ancient Greece knew no more bloodthirsty a warrior than Kratos, who for a time was the God of War. Mortal once more, Kratos withdrew from the ages-old clash between men and gods. But his solitude was broken when he was ripped through space and time. As the madness subsided, Kratos found himself in present-day Outworld, kneeling before Shao Kahn. To ensure his victory in Mortal Kombat, the emperor had invoked an ancient ritual, sacrificing the souls of his vanguard to summon and enslave the most powerful warrior of all time. But the spell alone could not contain Kratos, who soon regained his free will. Enraged by Shao Kahn's arrogance, Kratos vowed to rip the warlord's spine from his body. The God of War had returned to battle.||”|
|“||Shao Kahn was dead. The God of War had prevailed. The spell that had summoned him began to reverse itself. As he slowly faded from this place and time, Kratos was approached by Raiden and Fujin. Though he did not count them among his enemies, Kratos had never been beloved by these gods. He prepared for kombat. To his surprise, they bowed to him, a show of respect he had not seen from an immortal in many an age. Raiden explained that though his motives were not pure, Kratos had saved Earthrealm. He was owed a debt of gratitude. As he returned to his own world, Kratos nodded silently. Their change of heart would perhaps prove useful one day. A debt of gratitude is often dearly paid.||”|
- Kratos is a PS3 and PS Vita exclusive fighter.
- God of War III may have foreshadowed the fact that Kratos was going to be in Mortal Kombat, considering his fight with Zeus in the Chamber of the Flame being waged in a 2D environment. To drive the point further, Kratos uses several of the weapons from God of War III in Mortal Kombat and the Chamber of the Flame is also an arena in the game (also a PS3 and PS Vita exclusive).
- Similar to Soulcalibur: Broken Destiny, Kratos's Guest Appearance in MK9 is set somewhere assumingly and approximately sometime between God of War II and God of War III, yet he wields his God of War III weapons like the Blades of Exile, and according to his biography, he became Mortal again due to Zeus tricking him to drain his godly power into the Blade of Olympus in God of War II.
- Kratos and the Mortal Kombat character Scorpion share many similarities with one another; both of their families were murdered, both were betrayed by their masters, both are fueled by rage and vengeance, both crawled their way out of Hell/the Underworld, and both utilize weapons that involve the use of chains.
- According to Ed Boon, creator of Mortal Kombat, Kratos was a perfect fit for the Mortal Kombat roster. His gameplay is very similar to the gameplay of Mortal Kombat with combo attacks, grabs, and move schemes. Plus, his violence and brutal executions rival the gory Fatalities and savage fighting of the Mortal Kombat games.
- The Gamespot Mortal Kombat gameplay trailer saw Kratos using Apollo's bow, the Blades of Athena, Helios' head, the Blade of Olympus, the Nemean Cestus, Hermes' winged boots, and quicktime events.
- Despite the trailer footage, Kratos is shown wielding the Blades of Exile in-game.
- If one completes the Arcade Ladder mode with Kratos, during the cinematic where Kratos is shown finishing off Shao Kahn, the Blades of Exile will briefly be replaced by the Blades of Athena for three shots before returning to the Blades of Exile.
- Kratos also uses a gorgon head, as seen in his second fatality, but the head does not appear to be Euryale's nor Medusa's. It is neither pale green, like Euryale's, nor does it have red snakes for hair, like Medusa's. The head sort of resembles that of a Gorgon Serpent, but darker in color.
- When another fighter uses a Babality on Kratos, his infantile self will interact with a Medusa plush doll; removing its head just as he normally would when finishing off a Gorgon.
- When seen in the final cinematic sequence of his story, Kratos appears without the Golden Fleece on his arm.
- In the game, Kratos' Battle Cry, "You... will not see the end of this day," is actually a piece of dialogue taken from his first conversation with Zeus at the beginning of God of War III.
- Barring the death traps in MK: Armageddon, Kratos' stage, the Chamber of the Flame, is the only level in the series to have multiple stage fatalities.
- Sony demanded NetherRealm Studios to make Kratos have a different reaction towards certain Fatalities whenever they are performed on him. Some of the alterations are more fitted to how Kratos would normally react to different situations, others are as a sign of respect for both the series and character. Examples include:
- During Johnny Cage's second Fatality, Johnny does not implant a trophy into his head after karate-chopping it in half.
- During Mileena's first Fatality, Mileena does not eat Kratos' face; immediately throwing it to the ground instead.
- During Ermac's second Fatality, Kratos doesn't run around frightened after being shrunk. Instead, he will yell at Ermac.
- During Cyber Sub-Zero's second Fatality, Kratos does not pose strangely when Cyber Sub-Zero's shurikens plunge into his head, but simply falls down.
- During Noob Saibot's second Fatality, Kratos will barely react to having his lower torso separated from him.
- During Stryker's second Fatality, Kratos will not go searching for the bomb in his stomach; he will instead be in a fury.
- During Kung Lao's second Fatality, Kratos will neither panic nor flail his arms around during the process of being cut in half.
- During Skarlet's second Fatality, Kratos will attempt to break free from the blood pillars instead of panicking.
- During Kenshi's second Fatality, Kratos won't try to block Kenshi's attack.
- During Rain's first Fatality, Kratos will not bloat up while swallowing the water but rather stand in a, "T," stance before exploding.
- During Freddy Krueger's first Fatality, he will prepare himself for combat instead of wondering nervously of Freddy's absence.
- During Freddy's second Fatality, Kratos will not panic nor try to escape; instead, he attempts to grab Freddy before being killed.
- It is also interesting to notice that Kratos won't open his mouth when attacked in the head/face during any X-Ray. For example, in Scorpion's X-Ray, when Scorpion punches him in the face, he keeps his jaw closed. In Mileena's X-Ray, he won't scream when stabbed repeatedly, but keep his mouth closed in anger.