- Mortal Kombat (2011): "Shang Tsung has created many abominable creatures in his Flesh Pits, but none so twisted as Mileena. A fusion of Edenian flesh and Tarkatan blood, Mileena is both beauty and beast. This dichotomy has made her mind unstable; she is prone to fits of madness and savagery. Though she has the appearance of a mature woman, she is more child than adult--a blank slate conformed to Shao Kahn's will. Devoid of conscience or remorse, Mileena will butcher anyone to appease her beloved father."
- Mortal Kombat X: "Perceiving a lack of loyalty in his adopted daughter, Kitana, Shao Kahn ordered Shang Tsung to create a replacement, a daughter worthy of succeeding his rule. Shang Tsung fulfilled Shao Kahn's order by fusing Tarkatan DNA with genetic material stolen from Kitana to create a cloned hybrid: Mileena. Mileena is the best of both: bloodthirsty and vicious as a Tarkatan but possessing the Martial artistry and expertise of an Edenian. When Shao Kahn was killed by Raiden, Mileena took over as the ruler of Outworld. But when she refused to align Outworld with Earthrealm against Netherrealm's attack, she was deposed. She now leads a rebellion against the usurper Kotal Kahn's regime."
Mileena is first discovered by Kitana in Shang Tsung's Flesh Pits, after the Princess witnesses a sleeping clone lying on a table. When she awakes, she refers to Kitana as "Sister", and mockingly asks the Princess to come to her and become a family. Kitana is horrified by Mileena's creation, calling her a monstrosity, and attacks and defeats her. After confronting Shao Kahn about her creation, the Emperor reveals he knew about this the whole time. He sentences Kitana to execution for consorting with Raiden and the Earthrealm warriors. He then orders Shang Tsung to fetch his "true daughter" from the Flesh Pits. This prompts Jade to rescue Kitana, but having alerted the guards to her presence, Kitana pleads with Jade to escape and find help. Mileena then appears later in the Wastelands after finding Jade, remarking that whilst others pursue, she finds. She asks Jade to return with her to the "going away celebration" for her sister, cruelly teasing Jade about Kitana's execution. After defeating Mileena, Jade remarks that she is more of a sister to Kitana than Mileena. When the Earth warriors appear, Smoke confuses Mileena for Kitana, unaware that Mileena is Kitana's clone. This prompts him to attack Jade before she has the time to explain that Mileena is not the Princess. Mileena uses this opportunity to escape. She is later seen at the coliseum, standing beside Shao Kahn.
After Shao Kahn's defeat at the hands of Liu Kang, Baraka points out that Mileena is the next successor to the throne. Shao Kahn, however, emerges, thus keeping his reign as emperor. Mileena is quick to bow before her father who explains that Quan Chi healed his wounds. During the Earthrealm invasion, Mileena is spotted by Kurtis Stryker and Kabal witnessing the carnage unfold on the streets of New York. Stryker notes that Mileena is definitely a foe, whilst Kabal isn't sure (due to the small amount of clothing she is wearing). Stryker approached Mileena, and they face off, with Stryker proving victorious.
After Kabal is burned by Kintaro, and later revived by Kano, he forces the Black Dragon thug to lead him to the Emperor's throne room. When he arrives, Mileena is seen entering the room with Lin Kuei Cyborgs and Tarkatans, bringing with them the corpse of Motaro. She informs her Emperor that Raiden has slain the Centaur General. While Shao Kahn is transferring Shang Tsung's essence into the bewitched Queen Sindel, Noob Saibot and Mileena both intercept Kabal as he attempts to attack the Emperor. Kabal defeats them both in a two-on-one match and then escapes back into Earthrealm. Mileena is not seen again after her defeat by Kabal.
During the beginning of her her reign, she forced the Kytinn D'Vorah to kneel down and kiss her boot, and kicked D'Vorah's jaw when she attempted to do so, mockingly declaring D'Vorah her humble servant while being delighted she did not fight back.
Mileena's rule proves worse and more tyrannical than her father's and she was labeled the Mad Empress, driving Outworld to the brink of disaster. Kotal Kahn eventually usurped her rule, and with Reptile by his side as they confronted her in a coup d'etat, she was kidnapped by Kahn's followers and imprisoned, although she later escaped with the help of Tanya. Mileena was joined by former general of Outworld's army, Reiko, and Edenian traitor, Rain, and the rebels are forced into hiding for ten years.
Mileena would take Reiko as her lover and closest adviser, but she was unknowingly being manipulated by the former general for his own purposes.
Mileena is seen in Raiden's visions along with Reiko.
Mileena learns from Reiko that the Red Dragon have agreed to aid their cause, which pleases her. She then convinced Goro to join her cause after the Shokan Prince found her hideout in the Golden Desert, playing on Goro's desires for revenge on Kotal Kahn for reducing his people's status.
While Goro rallies the Red Dragon as Kotal Kahn comes to avenge his father's death, Mileena discusses with Reiko how she will regain her throne, but Reiko tells her that Goro will seek to challenge her rule. Mileena is confused by Goro's treason, but after Reiko tells her that Goro's betrayal of Kotal will lead to him betraying her, an enraged Mileena bares her fangs and vows to devour the Shokan's face. Clinging to her lover, Mileena croons that Reiko is the only one she can trust.
After Kotal Kahn defeats and cripples Goro, the temple Mileena used as a hideout in the Golden Desert is burned to the ground, but Reptile reveals that both Mileena and Reiko escaped beforehand.
Mileena fled to her keep in the Setian Valley with Rain's recovered, but badly burned body. Aware of the Shokan and Oni Warlord alliance that was currently attacking the capitol, Mileena speaks to Rain's comatose form, saying that under Kintaro's command they will never surrender and that Kotal Kahn will be dead that night. Believing she will finally reclaim her throne, Mileena begins to tell Rain that all their sacrifices will be worth it when Ermac arrives.
Angered at being interrupted, Mileena demands to know if Kotal Kahn's head is on a spike yet but is infuriated when she learns that Kotal has made an alliance with the Black Dragon to defeat the Shokan. Smashing a vase in rage, Mileena orders an attack to be mounted while Kotal's forces are still exhausted and demands to know where Reiko and the Red Dragon are, declaring it time for the general to make good of his many promises to her. Ermac informs her that Reiko is on Shang Tsung's Island when Rain suddenly regains consciousness.
Mileena explains to a confused Rain where he is and what happened to him when he suddenly asks where Reiko is. Mileena tells him Reiko is away and Rain reveals Reiko means to betray her and is working with the cleric Havik. Mileena knows of Havik as a 'spiritual advisor', having believed the cleric was using sorcery to strengthen their cause and admits that she is not so spiritual but trusted Reiko's judgement.
Mileena asks Ermac if any of the thousands of souls within him can reveal Havik's nature, but the construct only expresses confusion and chaos when Havik's name is mentioned. Overwhelmed over the fact that both Kotal and now Reiko have betrayed her, Mileena muses that this is why everyone calls her paranoid before ordering Ermac to gather the Tarkata and leads them for Shang Tsung's Island to find Reiko.
Mileena and her Tarkata horde arrive on the beach of the island, where Kotal Kahn and Reiko's forces battle each other. Mileena leads the charge of her followers onto the beach, tlling Kotal Kahn and Reiko that they will not kill each other, as the privilege of their death belongs to the true empress of Outworld.
Mileena's path to Kotal Kahn and Reiko is blocked by Skarlet, who calls their confrontation awkward. When Mileena demands to know why, Skarlet tells her that Reiko lost faith in her and turned to Skarlet. Mileena tries to tell Skarlet that Reiko is only loyal to himself and will betray her, but Skarlet laughs this off, calling her jealous before revealing Reiko has empowered her, and strikes Mileena back with a Blood Ball. Mileena's Tarkata forces rush to her defense, but Skarlet slaughters them all with ease.
Mileena recovers, telling Skarlet she has only become Reiko's puppet before throwing her sai and impaling Skarlet, though this fails to greatly wound her. Skarlet rushes at Mileena, telling her she is as much Shao Kahn's daughter as she is, but as Skarlet rants to her 'sister' over how she will share the throne with Reiko, their 'brother' Ermac intervenes, binding Skarlet with his telekinesis and opening her to Mileena's attacks. Mileena destroys Skarlet's legs with a Brutality, but as Skarlet weakly tells her this won't kill her, Mileena knocks her unconscious while vowing to torture her later.
Ermac then summons Shao Kahn's Wrath Hammer to Mileena, and after asking if she's practiced with it, Mileena proclaims that the empress does not need practice. Mileena then uses the hammer to strike Reiko, destroying half of his head. Believing him dead, Mileena is informed by Ermac that Reiko will rise again thanks to his soul being sustained by the Blood Code. Calling that a problem, Mileena confronts Kotal Kahn, holding her sai to his throat. Questioning him over calling her insane, Mileena lowers her weapon and tells him she is just mad enough to keep him alive so they can deal with Reiko together before dealing with each other.
Watching as Reiko was revived by the Blood Code with Kotal Kahn and Ermac, Mileena mocked his still regenerating face, saying even on her worst days she looked better than that. After Kotal Kahn explained that they needed to keep 'pushing' Reiko to have the Blood Code swallow his soul, Mileena asked what her usurper meant, and Kotal clarified that they needed to keep killing Reiko again and again. Saying, "With pleasure." Mileena approached Reiko with her father's Wrath Hammer, but stopped to threaten Kotal with it, making it clear she was not taking orders from him and that killing Reiko is why she came to the island.
Reiko renews his attack on the three, and when the power mad general struck both Mileena and Kotal with Ermac, the deposed empress lost her father's hammer, and found herself cut by Outworld's Kamidogu. As Reiko reveled in his supposed victory, revealing the origins of his delusions of godhood, Mileena drew her sai and struck with Kotal Kahn as Ermac tore Reiko's head off, with Mileena herself disemboweling Reiko with her sai while Kotal Kahn tore his legs off with his sun empowered blade. There's little time to revel in victory as Havik arrives, and though Mileena prepares to join Kotal Kahn in fighting the chaos cleric, she is one of the many struck by the Blood Code corrupted Raiden's lightning.
Mileena is knocked unconscious by Raiden's attack, and her body is taken to the throne room on Havik's orders. There, her blood is drawn in a ritual that will turn Reiko into the Blood God. Mileena regains consciousness during this and sees Reiko become the Blood God of prophecy.
As the Blood God, Reiko hungered for tributes, and contemplated sacrificing Mileena and Kotal Kahn to himself to satiate his new hunger, but Havik suggested they be publicly executed instead, and offered Mileena's Tarkata soldiers and Kotal Kahn's troops to him instead. After devouring all one hundred of them, Reiko's body began to tear itself apart, and the general gruesomely died as Havik revealed him to be nothing more than a pawn, with Mileena seeing the chaos cleric rip Shinnok's amulet from his body, his true goal the entire time.
Mileena watches Havik test the amulet's power on some Shokan scouts, and after the chaos cleric returns from destroying Queen Sheeva's ship, Mileena is stabbed by Raiden with one of the Kamidogu, enslaving her will to Havik's through the Blood Code. Now corrupted by Blood Magik, Mileena eyes burn red, tongue lashing as she snarls, "Every throne is a cage." Before Havik can drain Ermac of his souls to empower Shinnok's amulet, the Chaosrealmer's hand is severed by Takeda Takahashi using his new serrated whips.
Mileena remains by Havik along with the other Blood Code corrupted champions as Cassie Cage and Jacqui Briggs battle Takeda, only to be swiftly defeated. As Takeda moves towards Havik, the chaos cleric in mock shock asks where Mileena is, and the possessed empress announces her arrival as she lands a teleport kick on Takeda, leaving him open to be attacked by all of Havik's slaves.
Mileena observes Havik's torture of Takeda with Shinnok's amulet, and when D'Vorah arrives with reinforcements from Outworld, Mileena is attacked by Reptile with his acid spit.
Mileena manages to gain the upper hand in her battle with Reptile and viciously bites his neck before being freed from Havik's control. As the gathered fighters convene, Mileena sneaks away to free Ermac, using one of her sai to break bonds. Whispering to Ermac that it's time to go and that if they make haste, they can claim Z'unkarah's undefended throne. Mileena is infuriated when Ermac tells her he will not come with her and refuses to listen as he states Kotal Kahn to be the leader Outworld needs.
Mileena then flees Shang Tsung's Island alone.
Five years before the main events of the storyline, Mileena confronts Kotal Kahn, D'Vorah and Reptile as they are conspiring to dethrone her. Reptile intervenes and claims that her succession is illegitimate since she is an artificial creation and not Shao Kahn's biological daughter, but she retorts this by saying she is his heir by decree. Kotal gives her one final plea to listen to his advice, but she refuses and orders a Tarkatan to kill him. Ermac then betrays her, saying he will serve whom who he chooses, and they engage in a fight. Mileena’s army is wiped out, including Baraka, and she is imprisoned by Kotal Kahn, who becomes the new emperor of Outworld. At some later point in time, she is freed by a group that includes Tanya and begins a rebellion to reclaim the throne.
In the present day, Mileena launches a sneak attack on Kotal Kahn in Z'Unkahrah with Rain, Tanya and Kano, whom she paid to assassinate Kotal. However, all four of them are defeated by the emperor. Before Kotal Kahn can execute her, Mileena uses Shinnok’s amulet to protect herself. But she collapses afterwards and Rain escapes with her. Wielding the power of the amulet "without precision", Mileena also destroys Li Mei's village and causes its citizens to be displaced in Earthrealm as refugees. It is later revealed by Rain that wielding the amulet kills her slowly, part of his plan to take Outworld's throne for his own after both Kotal and Mileena have been disposed of.
The Special Forces learn of Mileena's location from Kano after he is captured, and Cassie Cage's group is sent to the Kuatan Jungle with Kotal Kahn's army to retrieve the amulet. Mileena stumbles upon D’vorah and Cassie in her tent while they are trying to steal Shinnok’s amulet and fights the former, but is defeated and brought to Kotal Kahn. He considers her unworthy to be executed by his hand, and ushers D'Vorah to do so. She unleashes her flesh eating parasites on Mileena through a kiss while Cassie and her group look on, visibly disgusted.
- Mortal Kombat (2011) (Non-Canonical): "Mileena killed the emperor in a fit of deranged fury. But she was unaware that her victory resulted from Shang Tsung's designs. He had imbued Mileena with the ability to drain Shao Kahn's dark magic, rendering him vulnerable. Now Shang Tsung was ready to execute the next phase of his plan: murder Mileena and take Shao Kahn's power for himself. But Mileena instinctively wielded her new dark power against the sorcerer. Shang Tsung's end came quickly. Mileena absorbed his soul, multiplying her strength. She then set out to claim an even bigger prize: the soul of a thunder god."
- Mortal Kombat X: "Overcome with exertion, Mileena collapsed and felt her soul gliding through the ether. She awoke in an incubation chamber. Nearby were countless others- each containing an exact copy of her. Mileena found she could read each being's mind, and they hers. They quickly realized the benefit of so many fierce warriors sharing one mind. As they plotted revenge on their enemies, the architect of the Mileena's awakening laughed quietly."