Jax, one of Earthrealm's champions in the 2021 Mortal Kombat movie and the eponymous video games, mostly relies on his own natural skills to battle other fighters, but he's also aided by two powerful bionic arms. Mehcad Brooks plays Jackson "Jax" Briggs in Simon McQuoid's live-action Mortal Kombat reboot. In the film, the Special Forces soldier helps Cole Young escape Sub-Zero before the latter freezes his arms and shatters them, leaving him for dead. However, Jax survives despite his injuries and receives the main source of his superhuman power in the form of cybernetic arms.
Like in the movie, the original Jax from the video games starts out as a regular human fighter when he's introduced in Mortal Kombat II. From then on, he uses robotic arms — sometimes implants, sometimes prostheses — to enhance his strength and store an assortment of weapons such as missiles, energy guns, plasma beams, and blades. He becomes stronger with each appearance and has influenced many crucial events in both Mortal Kombat timelines, which includes leading the Outer World Investigation Agency and starring in Mortal Kombat: Special Forces, set some time after Jax wounds Kano's eye.
The Mortal Kombat reboot focuses on Jax's first steps as an Earthrealm champion. So, his cybernetic arms are only equipped with the most basic enhancements. In fact, the arms that he receives at Raiden's temple are rudimentary and weak. What makes Jax a force to reckon with is his arcana, which transforms his prostheses into highly capable weapons. After receiving the upgrade, he's able to break Reiko's hammer effortlessly and employ his gory "Head Clap" fatality on him. Although his arms are the most visible improvement, Jax's feats of power suggest his whole body got a boost in strength and endurance.
Even without counting Jax's powerful arms, his Special Forces training and natural fighting skills make him an adept fighter. He's extremely strong, skilled in hand-to-hand combat, and an expert when it comes to ranged weapons. The 2021 Mortal Kombat movie doesn't give him enough time to showcase all of these talents, but future sequels could see him integrating them to his new combat style once he has gotten used to his enhanced extremities. In the future, Jax's arcana powers could also provide him with high-tech weapons that resemble the ones he usually uses in the video games.
While other powerful characters like Scorpion, Sub-Zero, and Goro owe their powers to either supernatural sources or their own natural physiology, human characters such as Jax Briggs, Sonya Blade, and Johnny Cage have trained to be on the level of Mortal Kombat's best champions. Of course, their arcana is a great aid, but Shang Tsung has many reasons to fear them even without additional abilities. Future live-action sequels will probably add more skills and special powers to Jax's move set when his arms develop more advanced features, and perhaps Jax's daughter Jacqui Briggs will come along with him.