- Mortal Kombat X: "Cassandra Carlton Cage, the daughter of Johnny Cage and Sonya Blade, has a lot to live up to. Her parents were among the few kombatants to survive the wars against Outworld and Netherrealm, and were instrumental to Earthrealm's victories. Cassie is as strong-willed--and occasionally hotheaded--as her mother; and quick-witted as her beloved father, which makes her popular among her Special Forces unit. But these traits hide a seed of self-doubt cultivated by the demanding nature of her commanding officer: Sonya."
- Mortal Kombat 11: "The offspring of Johnny Cage and Sonya Blade laid the smackdown on Shinnok a few years back, but even that wasn't enough to escape the shadow of her legendary parents. Whenever Cassie isn't defending Earthrealm, she's fighting to prove worthy of their legacy."
Cassie is born to Johnny and Sonya sometime after Shinnok’s defeat. At some unknown point in her life, her parents split because her mother spends more time at work than with her family, and this upsets her father.
Cassie makes her first actual appearance facing off against her friend Jacqui Briggs in her father Johnny Cage's condo. Both girls spar, exchanging blows both verbal and physical when Cassie suddenly pulls off her father's Shadow Kick, shocking them both. Jacqui points out that Cassie broke one of Johnny's awards but Cassie dismisses this, unconcerned at her father's reaction, though goes on a tirade about how strict her mother Sonya is.
Later that night, Cassie takes Jacqui to a 21-and-over fight club. Though Jacqui is nervous about getting caught, Cassie is confident and boldly cuts through the line to the bouncer at the door, slipping him money to let them in. Cassie takes Jacqui to the arena, showing her a match between two women while stating her confidence in their ability to take them on. Cassie goes to use the bathroom and sign up, pausing to slip on her gloves when Jacqui catches up with her, panicking as she tells Cassie it's not MMA but a deathmatch.
Cassie is disbelieving until an announcer confirms Jacqui's words and Cassie curses as the spotlight lands on them and two bouncers grab the girls. Cassie is tossed in the cage and after the announcer makes fun of her father's acting, Cassie responds by flipping off the crowds and declaring herself the best fighter there. Cassie is shocked when the announcer reads off her opponent's victories and the cryomancer Frost appears in front of her.
Cassie is on the receiving end of a severe beating at Frost's hands. Cassie is brought to her knees and about to be finished by Frost when she manages to land a headbutt and sweep kick on her and choke her into unconsciousness with a submission hold. The announcer and crowds demand Cassie finish Frost but Cassie refuses. When both Cassie and Jacqui are threatened, Cassie angrily complies and puts her foot down on Frost's throat. Cassie whispers an apology to her opponent, but before she can finish her, the roof to the club explodes. Cassie is relieved, thinking it's her mother at first, but when sees two warriors armed with an axe and swords who begin to slaughter the crowd, Cassie panics and begins dragging Frost off with her to escape.
Jacqui manages to reach her and the two girls flee outside with Frost. When they stop to catch their breath, Cassie explains to a questioning Jacqui that she wanted to save Frost in response to nearly killing her before apologizing to Jacqui for bringing her to the club. The two warriors confront the girls, and after revealing their affiliation with the Black Dragon, Cassie screams at Jacqui to run again. As they run, Cassie asks for her phone from Jacqui and snaps a shot behind herself as part of a trail, admitting they can't hope to outrun their pursuers. Cassie and Jacqui are then sucked into a portal for Outworld, with Cassie managing to drop her phone just before she disappears.
Cassie and Jacqui are revealed to be in Outworld, hands tied with rope and cloaks draped over their heads, being led by Black Dragon soldiers deeper into a jungle. Cassie stages an escape attempt, faking a sprained ankle to get the drop on a Black Dragon before headbutting his jaw and kicking him in the groin, demanding to be let go. Cassie's escape ends before it can begin when Kano knocks her unconscious with a single eye beam from his optic implant. Cassie's unconscious body is carried by another Black Dragon soldier, but he is killed and Cassie is dropped onto the ground when Red Dragon forces led by Mavado arrive, having come for the girls.
Cassie and Jacqui are faking being unconscious as the Black and Red Dragon clans heatedly debate who will take possession of them. Cassie knows the clans will soon fight and is flabbergasted when Jacqui suggests they run blind with their hands bound. When the two clans go to battle, Cassie and Jacqui get up, with Cassie agreeing to run. As she's asking which way, the gunslinger Erron Black, who was the true perpetrator of their kidnapping, frees them from their bounds, saying he can get them out of there if they agree to fight. Jacqui chooses to fight Erron instead while Cassie fights of Red Dragon soldiers. When Kano knocks Jacqui down with a single punch to get the Portal Stone from Erron, Cassie urges her friend back up while getting one of the Black Dragon soldiers rifles. After Kano abandons Black and Mavado cuts the gunslinger down with his hookswords, Cassie gets the Red Dragon's attention before opening fire along with Jacqui, shooting down several of Mavado's soldiers but failing to hit Mavado himself, using up all their ammo.
Mavado leaps at the girls, cutting Cassie's arm with his hooksword but Jacqui catches him a hold, allowing Cassie to deliver a kick to his kneecap, shattering it. Cassie picks up one of Mavado's swords as Jacqui shouts at her to finish him. Without hesitation, Cassie swings the hooksword in a rising slash, cutting Mavado's abdomen open, spilling his internal organs out and killing him instantly. Despite killing Mavado, Cassie and Jacqui are captured by the remainder of his forces and brought to Shang Tsung's Island and presented to Reiko and his spiritual adviser, the chaos cleric, Havik. Cassie is seen inside her prison cell on Shang Tsung's island, chained and disheveled as Havik discusses with Skarlet the girl's heritage and untapped power, noting that fighting will bring it out and allow the chaos cleric to claim it for himself.
Cassie is then moved to another area and chained to the floor, forced by Havik to watch as Skarlet pummels Jacqui. Cassie calls to her friend to run but Jacqui is knocked unconscious, much to Cassie's horror. Cassie asks Havik why he is doing this to them and the cleric of chaos' response is because her father is Johnny Cage. Cassie mockingly asks if Havik wants and autograph and Havik explains he wants power, specifically the power in Johnny Cage's bloodline, which allowed him to defeat Shinnok. Havik knows that this power can be unleashed when those possessing it see their loved ones in danger and asks Cassie if Jacqui's life means nothing to her.
Cassie pleads with Havik, saying she doesn't have power like her father's. Havik muses that it may have skipped a generation before deciding that Cassie hasn't suffered enough to unlock it yet. Cassie is eventually returned to her cell when she hears footsteps outside the door and leans closer towards it. The door violently opens, catching Cassie on her nose before a boot suddenly strikes her jaw. Cassie is shocked when she sees it is Jacqui attacking her, her best friend's eyes glowing red as she suddenly grabs Cassie and tells her that Skarlet will save them through the Blood Code. Cassie calls that insane when Skarlet arrives, ordering Jacqui to hold her. Cassie struggles in vain as Skarlet tells her that her parents will soon arrive. Cassie starts to threaten Skarlet but screams as Skarlet stabs her in the chest with a Kamidogu, inflicting the Blood Code on Cassie.
When Cassie's parents arrived on Shang Tsung's Island, Cassie greeted her parents, revealing her corrupted state under the Blood Code's influence. Declaring the island to be her and Jacqui's new home and Reiko their new god, Cassie prepared to kill both of them to prove it. Cassie faced her mother, and though Sonya tried to reason with her by peacefully telling Cassie she was there to take her home, Cassie only demanded to know "Which home?" before attacking her mother. Though under the Blood Code's influence, each of Cassie's attacks were parried by Sonya, who then knocked Cassie to the ground with ease. During their battle, Cassie would witness Mileena and the Tarkata's arrival to the island.
Cassie continues to fight her mother, but is on the receiving end of a kick and energy blast. Cassie recovers however, the Blood Code corrupting her enabling her to keep fighting. Cassie would later witness a Blood Code corrupted Raiden's arrival as the thunder god single-handedly incapacitated every fighter present in a hail of blood red lightning bolts. Cassie stands by Havik's side observing Raiden's attack on Kotal Kahn, Mileena, and her parents. When Havik has the Red Dragons collect the unconscious fighters and take them back to the throne room, Cassie joins Havik as the chaos cleric prepares the ritual to ascend Reiko to godhood. Cassie participates in the ritual, stabbing Reiko with one of the Kamidogu after he drinks a goblet of blood and witnesses the general's ascension as the Blood God.
Cassie alongside Jacqui and Raiden watch as Reiko revels in his newfound godhood and devours a hundred of Mileena and Kotal Kahn's forces as tributes to himself. When Reiko begins to suffer from the agony of starvation for tributes and his body begins to tear itself apart, Cassie, speaking in union with Jacqui and Raiden, reminds the general that the Blood Code only gives power through suffering. Cassie witnesses Reiko's gruesome death and execution at Havik's hands as the chaos cleric rips Shinnok's amulet from his body, his true goal the entire time.
Cassie watches along with the rest of the Blood Code enslaved champions as Havik demonstrates the amulet's power by unleashing it on some Shokan scouts that had been spying on them. Cassie is present on the beach when Havik attacks Queen Sheeva's ship with the amulet, sharing a high five with Jacqui when it explodes. Returning to the island throne room, Cassie takes one of the Kamidogu and stands over her bound mother, stabbing Sonya at Havik's bidding and enslaving her as well to the Blood Code. As Havik prepares to charge Shinnok's amulet with Ermac's souls to empower it to breach Raiden's cosmic barriers that protect the Netherrealm from invasion, Takeda Takahashi arrives, cutting off the chaos cleric's hand that holds the amulet with his new whips. At Havik's bidding, Cassie charges for Takeda alongside Jacqui, mockingly pitying him for growing up surrounded by killers. Takeda swiftly catches Cassie with one of his whips and throws the possessed girl into Jacqui, and then gets both girls in submission holds, knocking them out.
The Blood Code corrupted Cassie regains conscious as Havik tortures Takeda with Shinnok's amulet, only to have the relic shot out of his hand by Erron Black, who arrives with D'Vorah and reinforcements from Outworld. Cassie is used by Havik to greet the Outworld fighters, and Cassie joins with Jacqui in battling the Tigar Shokan Kintaro, landing a punch to the Shokan champion's groin. Cassie continues to battle Kintaro alongside Jacqui, and when her possessed mother joins, Cassie helps Jacqui restrain Kintaro, allowing Sonya to rip the Shokan champion's head clean off. Moments later, Cassie and all others under Havik's control are released from the Blood Code, and Cassie is shocked to see her mother Sonya. As the gathered warriors convene in small groups, Cassie sticks close to her father and Jacqui until her mother pulls her aside.
Cassie bows her head in shame as Sonya begins reprimanding her for leaving the base without telling anyone, but when Cassie calls Sonya by her rank, Sonya reminds Cassie she's her mother and pulls her into an embrace, telling her she loves her too much to lose her. Cassie happily returns the embrace, calling Sonya mom and telling her she loves her too. Cassie is in the middle of telling Sonya of her death match when Kotal Kahn and Raiden arrive to speak with Sonya. Saluting her mother, Cassie happily returns to her father and Jacqui.
A week after Reiko's death, Cassie is with her parents watching as Jacqui reunites with her father and mother. Though Johnny asks Cassie if she wants to have a father-daughter retreat, Cassie declines, eager to begin spending more time with her mother on the base, and happily falls in line when Sonya calls for her to move out.
Cassie becomes a sergeant in the Special Forces under her mother, who is a general. Her father puts together a team consisting of Jacqui Briggs, Jax Brigg's daughter and Cassie's best friend, Kenshi’s son Takeda Takahashi, Kung Lao’s younger cousin Kung Jin, and herself as the leader.
For their first mission, Cassie are her team are sent to the Lin Kuei temple to assess if Sub-Zero is still an ally. She tries to lead the team for a sneak attack, but Jin does not listen and approaches the Grandmaster as he and his men are meditating. As they are suddenly surrounded, Cassie tries to reason it out with Sub-Zero. When he refuses, Jin and the others attack without Cassie’s order. All four of them are defeated by Sub-Zero and are bounded. Cassie tells him that he will be in trouble if he kills them. Much to their surprise, he agrees and sets them free. Upon spotting Johnny, they realize that the mission was merely a training exercise so Sub-Zero can test their skills as a team. He tells Cassie that she and her allies show promise, but they will fall short if they do not start functioning as one.
The team is then called back to headquarters by Sonya, where they meet Li Mei, the leader of refugees from Outworld. From her, they learn that Mileena has Shinnok’s amulet and cannot control its power, which is why Li Mei’s village was destroyed. To confirm with Kotal Kahn that Li Mei’s story is true, Sonya sends Cassie and her team to Outworld. After crossing worlds, the team is "greeted" by Erron Black, an Earthrealm mercenary working for Kotal Kahn. He demands for them to state their business, and Cassie replies that they are emissaries sent by Raiden carrying his official seal. Erron does not believe them, but Jin convinces him to spare them and take them to Kotal Kahn.
Along the way, they see a bread thief about to be executed. Jin intervenes, causing a fight with the team and the Outworlders. After Jin defeats Erron Black and Ferra and Torr, D'Vorah arrives and tells them to wait while she fetches the emperor. Cassie then angrily demands that Jin explain why he will risk it all for a bread thief, and his reply is that not all thieves are irredeemable since he was a thief himself. Once Kotal Kahn arrives, Cassie informs him about the Outworld refugees and that Mileena has the amulet. However, the emperor begins to suspect them of aligning with the rebel leader. Jin then asks for a match to absolve the team of all accusations. Kotal Kahn accepts and Jin wins the match. It is then decided that they will work together to stop Mileena’s rebellion.
Cassie then receives a call from Sonya, who has just received information from interrogating Kano. Mileena’s location is in the Kuatan Jungle, surrounded by several Tarkatan troops. As Kotal Kahn prepares for an attack, D'Vorah suggests that she sneaks into the camp to steal the amulet. Cassie then insists that she go with the Kytinn, and although D’vorah initially refuses, Kotal Kahn allows it since he is indebted to her team. As the battle ensues, Cassie and D'Vorah sneak into the rebel camp, where they ambush Rain. He confesses that he is the one who advised Mileena to use Shinnok’s amulet, knowing that it kills her each time she uses it. Once both sides have fallen, he plans to take the throne himself.
Then Cassie is ambushed and knocked out by Tanya, leaving D'Vorah to fight and defeat both Edenians on her own. Just as she prepares to kill them, Cassie stops her and they continue into the main tent. D'Vorah uses her insects to open the lock on the chest containing the amulet, much to Cassie’s disgust. However, Mileena arrives and the Kytinn battles her, leaving Cassie to deal with the lock. After D'Vorah defeats Mileena, the rebel leader is brought bound to Kotal Kahn. Cassie and her team watch in horror as D'Vorah kills Mileena with her flesh-eating parasites. They then prepare to go back to Earthrealm with the amulet, but Kotal Kahn has them captured, stating that he does not trust them with the amulet and he plans to use them as bait to lure Raiden.
The four of them are locked inside a ship, and they each reveal a little bit about themselves. Cassie confesses that it is tough for her being Sonya’s daughter, and she always feels like a second-rate Cage. As an Osh-Tekk comes down to toss them some food, Takeda overloads his senses using his telepathy, rendering the guard unconscious, and he steals the keys and frees himself and his teammates. As they make their escape, they spy on Reptile, Ermac, and Erron Black, and they learn that D'Vorah has betrayed Kotal Kahn, taking Shinnok’s amulet with her. Then they fight Kotal Kahn's henchmen, this time as a team. After Takeda defeats all of them, the four of them escape before their enemies recover.
In the jungle, they contact Kenshi and inform him that D'Vorah is on her way to the Sea of Blood. Jax, who is with the blind swordsman in the Netherrealm, deduces that the Kytinn is on her way to meet with Quan Chi to free Shinnok from his amulet. The four of them continue to pursue D'Vorah, but her trail goes cold. Later, when Quan Chi is captured by Jax, Cassie tells her mother that they will try to capture the Kytinn, but Sonya tells her that they do not have time and orders her team to return to Earthrealm so they can regroup and redeploy. But upon their return, they find everyone beaten on the ground, Quan Chi beheaded, and Johnny missing. Cassie rushes to her mother and asks her where her father is. When Sonya slips into unconsciousness, Hanzo Hasashi answers Cassie that Johnny has been captured by the resurrected Shinnok and is being brought to the Sky Temple.
As the only remaining defenders of Earthrealm, Cassie and her team head for the Sky Temple. Suddenly, they see the sky becoming red due to Shinnok corrupting the Jinsei. After Jacqui lands the ship, Cassie tries to repair it but to no avail. Kotal Kahn then appears and attacks them, mistakenly believing that they have aligned with D'Vorah. The team retreats into the woods, allowing them to ambush the Outworld army. Jacqui manages to tell Kotal Kahn that Shinnok is corrupting Earthrealm’s life-force and he should join them. But the emperor refuses, believing that he can strengthen Outworld’s defenses by bringing their heads to the fallen Elder God. Cassie’s team is then surrounded by the Outworld army, but they are suddenly rescued by Sub-Zero and the Lin Kuei. The Grandmaster praises the four of them four standing together against formidable odds and allows them to continue to the Sky Temple while he pushes Kotal Kahn back to Outworld.
Arriving at the temple, the team spies on D'Vorah and the revenants, learning that Shinnok plans on attacking the Heavens to defeat the Elder Gods after completing his invasion of Earthrealm. Knowing that they have no time to lose, Cassie and her team prepare to launch a surprise attack. But their cover is blown when Takeda slips on a rock and hangs on the cliff for life. As Jacqui tries to pull him up, Cassie and Jin engage in battle with Sindel and Kitana respectively.
The former Edenian queen boasts of killing Sonya's friends in a blink of an eye, and says that she will kill Cassie so she will join them. But the young soldier defeats Sindel, refusing her offer. After Kitana knocks out Jin, Cassie fights her with Jacqui and Takeda, but the princess wounds her companions. She defeats Kitana to prevent her from killing anyone. As she and Jin help their teammates up, the are spotted by the other revenants. Jacqui and Takeda urge the others to go on ahead and let them buy time. Although worried for her friends, Cassie complies and she and Jin head for the Jinsei Chamber.
Inside, they find the corrupted Shinnok inside Earthrealm’s infected life-force, Raiden defeated and bound, and D'Vorah inflicting her flesh-eating bugs on Johnny. Cassie and Jin proceed to fight the Kytinn, but the archer is knocked out, leaving the soldier alone in defeating D'Vorah. She then rushes to her father and tries to set him free, but he tells her to get Shinnok and that he loves her before passing out.
The fallen Elder God then emerges from the Jinsei, intent on killing both Cassie and Johnny. Cassie does her best in fighting Shinnok but is easily knocked aside and she is forced to watch as Shinnok tortures Johnny. Enraged, Cassie unlocks her inherited powers, which protect her from Shinnok’s attack. With her newfound strength, she defeats the fallen Elder God and renders him unconscious. After Jin recovers and joins Cassie, they free Raiden and help him to the Jinsei, watching as he heals Earthrealm’s life-force. Then they bring him back out, and Cassie rushes to her father while Jin tends to the Elder God. Sonya later arrives with the Special Forces and joins with her daughter and Johnny, and the family is happily reunited.
Part 1: Mortal Kombat 11
Following her victory over Shinnok, her mother Sonya promotes her to Commander. They began their assault on Netherrealm, to prevent their war. On the way, she defeated the Revenants, Kabal and the empress, Kitana. During the ambush, the Revenant Liu Kang buries her mother and her soldiers under the rubble. She tries to save her, but Sonya tasked her to leave, before she activates the detonator. They escaped the Netherrealm and successfully destroyed the temple, but at the cost of her mother's life.
The next day, Kronika's time-quake is in full effect on Earthrealm, bringing the past selves of Cage, Jax and Sonya. But Dark Raiden is erased from existence. During the past Raiden's arrival on Earthrealm, she told him how he became a different person. Young Sonya learns that her future self was recently killed in action, and verbally tears into Cassie for abandoning her mother, causing Cassie to fire back that she only did so on her mother's orders. Cassie, Sonya and the Special Forces are under attacked by The Cyber Initiative, along with Kano and his past self. The elder Johnny finds Cassie, alive but injured, who informs him that past Sonya has been captured. Johnny heads out to rescue her, commandeering a tank on his way to deal with the Cyber Lin Kuei.
The Special Forces have no choice but to watch as the Black Dragon leave with the past Sonya and Johnny in their clutches. Fortunately, Cassie places a tracker on their aircraft as it flies away. However, their troubles are not over, as Kano had fitted Sektor with a nuclear bomb, which he activates during his exit. They are saved by the timely arrival of Raiden, who teleports them to the Shirai Ryu's fire garden seconds before the explosion. Cassie then leads the Special Forces on a rescue mission to save past Johnny and Sonya from the Black Dragon.
A medical crew then tends to Johnny and Cassie, with Johnny inviting Sonya to dinner as gratitude for saving his life. But before the trio can escape, Geras arrives to confront Sonya, telling her that Kronika has sent him to avenge Shinnok's defeat at the hands of Cassie Cage. After he's defeated, Cassie rams him with a forklift, pinning him to a garage door, before throwing a grenade in for good measure. Sonya apologizes to Cassie, stating that she was wrong to blame Cassie for the death of the older Sonya. As the two embrace, Geras begins to regenerate, confirming Liu Kang and Kung Lao’s warning about him, and forcing the trio to evacuate immediately.
Back to the Fire Garden, Cassie tells Raiden that Kronika has her crown. Raiden tells her that he cannot beared the dark power of Shinnok's amulet. Moments later, Cassie, Jacqui and younger Jax approaches Raiden, who recalls other timelines with him fighting Liu Kang. He soon relinquishes the amulet and tells a confused Liu Kang and Cassie that he has realized that Kronika has been manipulating them to fight in every timeline, with Liu Kang dying in every one.
After the revelation and with Kharon recruited, the younger Jax, Cassie, Jacqui, Raiden, Scorpion, Sub-Zero, Kung Lao, Kitana, Sheeva, Jade, and Baraka lead a joint Earthrealm and Outworld task force to assault Kronika's keep. But due to Kronika's hourglass, she has fallen victim to the temporal reversion alongside the coalition forces.
Part 2: Aftermath
As Jacqui, Nightwolf, both Jax's, and the Special Forces prepared for their final assault at Kronika's Keep, they are still waiting for Sheeva and her Shokan army. As the portal opens, the Shokans, who pledged their allegiance to Shao Kahn and Sindel, attacked the Special Forces. Cassie was then defeated and captured along with Sonya Blade and Johnny Cage, leaving their fates unknown.
- Mortal Kombat X (Non-Canonical): "Cassie Cage's impressive victory over Shinnok led Raiden to give her a new important task: hunting down a soul stealer. Cassie did not have to be told that the suspect could be a resurrected Shang Tsung. Having tracked him from the site of his last known assault, Cassie confronted the withered old man. He fought desperately but was ultimately defeated. As the old man lay dying before her, Cassie asked his name. With a mixture of sadness and relief, he whispered, 'Shujinko'."
- Mortal Kombat 11 (Non-Canonical): "For the second time in my life, I kicked the living shit out of an immortal. My prize? The Hourglass. Now I can change history! Talk about ridonkulous cosmic power. But despite what you may think about Beverly Hills girls, that is SO not my style. The Chosen One thing is for the Liu Kangs and Kitanas of the world. In the next timeline, all I want is to be a model soldier. To command the next generation of Special Forces. We were born to defend Earthrealm! Just like the heroes that inspired me...my parents. Okay, so there's one more thing I want: My mom back. Not just for me, but for dad. He and my mom deserve a happily-ever-after retirement. We'll never know how different things were the last time around. But we'll be together. A family. And that's all that matters."