Lieutenant Sonya Blade is one of the main heroes of the MK series. She is a second-generation United States Special Forces officer who formerly served under her own father, Major Herman Blade. (Other family members include Sonya's mother, Erica, and twin brother, Daniel.) More recently, she joined the Outer World Investigation Agency. Her impulsiveness is catalyzed by her superior and good friend Major Jackson "Jax" Briggs. Sonya represents a emancipated and headstrong woman, who despite stubbornness and pride cares about the lives of her friends and comrades. She has a long-standing enmity with the thug Kano, who stands for everything Sonya despises.
In the original Mortal Kombat, Sonya and her team were pursuing Kano, the leader of the Black Dragon international crime organization. After he jumped onto a ship, they followed him to a remote island where Shang Tsung's Mortal Kombat tournament was underway. Upon arrival, they were ambushed by Tsung's personal guard. To keep her team safe, she agreed to compete in the tournament. Shang Tsung, however, had no intention of fulfilling his end of the bargain and had her unit killed. After Shang Tsung was defeated by Liu Kang in the final battle, Sonya teamed up with Johnny Cage and Kano despite her hatred of the latter, to fight Goro on the bridge high above the pit. During the battle, the island started to crumble and she and Kano were taken prisoner to Outworld by Shang Tsung to appease the Outworld emperor, Shao Kahn. Sonya was able to send a signal to her superior Jax from Outworld and, during the events of Mortal Kombat II, he traveled there to find her. Jax made contact with the other Earthrealm warriors and together they learned of Kahn's scheme to invade Earth. It is known that before being captured, Sonya and Kano were forced to put their differences aside and work together to survive in Outworld. She was later freed by Jax who arrested Kano, but as soon as they had passed through the portal to Earth Kano escaped and ran back into Outworld.
Sonya was one of a few selected Earthrealm warriors whose souls were not taken following Kahn's invasion of Earth in Mortal Kombat 3. She encountered Kano on top of a skyscraper near his fortress and after a fight hurled him off the roof to his apparent death. In Mortal Kombat 4, after her journey into Outworld and Shao Kahn's near destruction of Earth, Sonya became a member of Earth's own Outworld Investigation Agency (OIA). The Black Dragon kept crossing her path, however, and its last known member (Jarek) had fled to Edenia while Sonya was chasing him. This led Sonya and Jax to team up with Raiden and Liu Kang to free that realm from the Fallen Elder God Shinnok's grasp and to prevent him from coming to Earth. After Shinnok's defeat, in which Jarek had reluctantly participated to save himself, Jarek tried to kill Sonya but Jax interfered and dropped him off a cliff. After returning to Earthrealm Jax and Sonya found Cyrax malfunctioning in a desert. The two brought the cyborg back to the OIA headquarters where they were able to restore Cyrax's humanity. Cyrax then joined the agency.
In Mortal Kombat: Deadly Alliance, while on an assignment in the East, Sonya received a distressing message from Jax that the OIA had been destroyed by an accomplice of Shang Tsung and Quan Chi. She was then visited by the God of Thunder, Raiden, who asked for her aid against the Deadly Alliance and instructed her to meet with the other heroes on Shang Tsung's abandoned island, where she developed a small rivalry with Frost. To earn the right to pass into Outworld, each warrior had to defeat a representation of his or her adversary - to her surprise, it was a stranger with an image of a red dragon on his back. Sonya was unable to find the two missing OIA agents, Cyrax and Kenshi and was killed along with Jax and Cage in battle with the Deadly Alliance's Tarkatan forces. The Deadly Alliance's victory was short-lived, as Onaga reclaimed Outworld, as well as the amulet. With his ability to raise the dead at will, he resurrected and enslaved Sonya and her fallen comrades. (As Sonya and her comrades appear normal in Mortal Kombat: Armageddon, it is likely that Ermac and the spirit of Liu Kang had freed them from Onaga's control.) In Mortal Kombat: Armageddon, Sonya returns to Earth after Onaga's defeat, with the intention of continuing her assault on both the Red and Black Dragon clans, only to be forced to focus on the newly-established threat. In her absence, the Tekunin had grown large enough to disrupt Earth civilization and had violated law by engaging in illegal inter-realm alliances with unknown parties. Sonya succeeds in downing the Tekunin's flagship, helmed by their Grandmaster Sektor himself. She then sends a team led by her partner Jax in to hunt for survivors, but they mysteriously vanish and Sonya fears the possibility of Jax's death. She tracks the signal of a homing beacon placed on Taven (escaped thanks to her intervention) and eventually confronts him in Arktika to get information out of him, but is beaten.
In the non-canonical crossover game Mortal Kombat vs. DC Universe, Sonya appears as one of the warriors representing the Mortal Kombat Universe. In the story mode, Sonya is investigating the dimensional imbalance. After defeating Catwoman, Baraka and Captain Marvel and Green Lantern, Sonya and Jax return to their base to use their own teleportation machine to try to get to the other dimension, freeing the captive Sub-Zero along the way. When she finds Jax at the hands of Green Lantern, Sonya once again challenged him but is defeated and imprisoned, but then both of them manage to escape together. When the Earthrealm's heroes and Outworld's villains join forces against the invaders from the other universe, Sonya reluctantly teams up with Kano to track a foreign energy signal, but they confronted and defeated by the Joker and Deathstroke. When both sides finally decide to meet for one last battle, Sonya once again fights Catwoman. In the end, she is knocked unconscious while Raiden and Superman proceed to fight Dark Kahn. After Dark Kahnâ€™s defeat and the separation of the universes, Sonya stands alongside her allies and enemies to see a powerless Darkseid left behind in Shao Kahnâ€™s palace.