Cyrax is unit LK-4D4, the second of three prototype Cybernetic Ninjas built by the Lin Kuei. Like his counterparts, his last program is to find and terminate the rogue ninja Sub Zero. Without a soul, Cyrax goes undetected by Shao Kahn and remains a possible threat against his occupation of Earth.

In failing to convince his superiors of the coming Outworld invasion, Jax prepares to covertly for the future battle with Kahn's minions. He fits both arms with indestructible bionic implants. This is a war Jax is prepared to win.

As a chosen warrior, his identity is a mystery to all. It is believed he is a survivor of an attack by Shao Kahn's extermination squads. As a result, he is viciously scarred, kept alive by artificial respirators and a rage for ending Shao Kahn's conquest.

Kano was thought to have been killed in the first tournament. Instead, he is found alive in the Outworld where he again escapes capture by Sonya. Before the actual Outworld invasion, Kano convinces Kahn to spare his soul. Kahn needs someone to teach his warriors how to use Earth's weapons... Kano is the man to do it.

Kung Lao's plan to reform the White Lotus Society comes to a halt when Shao Kahn's invasion takes the earth by storm. As a chosen warrior Kung Lao must use his greatest fighting skills to bring down Shao Kahn's reign of terror.

After the Outworld invasion, Liu Kang finds himself the prime target of Kahn's extermination squads. He is the Shaolin Champion and has thwarted Kahn's schemes in the past. Of all the humans, Kang poses the greatest threat to Shao Kahn's rule.

In the realm of the Outworld, Motaro's race of Centaurians has long since come into conflict with the Shokan. When Shao Kahn formed special extermination squads to eliminate the chosen warriors of Earth, Motaro was appointed to head this elite group of savage warriors.

Bio taken from MKTrilogy.

Nightwolf works as a historian and preserver of his people's culture. When Kahn's portal opens over North America, Nightwolf uses the magic of his Shamen to protect his tribe's sacred land. This area becomes a vital threat to Kahn's occupation of Earth.

Sektor is actually the code name for unit LK-9T9. He was the first of three Prototype Cybernetic Ninjas built by the Lin Kuei. Sektor was once a human assassin trained by the Lin Kuei. He volunteered for automation because of his loyalty to the clan. Sektor survives the Outworld invasion — he has no soul to take.

Tsung is Shao Kahn's lead sorcerer. He once fell out of favor with his emperor after failing to win the Earth Realm through tournament battle. But the ever scheming Shang Tsung is instrumental in Kahn's conquest of Earth. He has now been granted more power than ever.

Long ago, Shao Kahn rose to power in the Outworld, usurping the realm from Kitana's parents and taking Queen Sindel for his bride. Then she died. Now, centuries later, Sindel is reborn. And since Shang Tsung failed to win the Earth Realm through Mortal Kombat I and II, her rebirth is the means by which Kahn will finally seize the planet forever…

Bio taken from MKTrilogy.

Sheeva was hand picked by Shao Kahn to serve as Sindel's personal protector. She becomes suspicious of Shao Kahn's loyalty toward her race of Shokan when he places Motaro as the head of his extermination squads. On the Outworld, Motaro's race of Centurions is the natural enemy of the Shokan.

Sindel once ruled the Outworld at Shao Kahn's side as queen. Now 10,000 years later after her untimely death, she is reborn on Earth with evil intentions. Sindel is the key to Kahn's occupation of Earth.

Smoke, unit LK-7T2, is the third prototype cyber-ninja built by the Lin Kuei. He tried to escape the automation process with Sub-Zero but was captured. His memories were stripped away, leaving behind an emotionless killer. However, Sub-Zero believes that within this machine is a human soul trying to escape.

Sonya disappears in the first tournament, but is later rescued by Jax. After returning to Earth, she and Jax try to warn the U.S. government of the looming Outworld menace. Lacking proof, they watch helplessly as Shao Kahn begins his invasion.

When the Outworld portal opens over a large city in North America, panic and chaos rage out of control. Kurtis Stryker was the leader of the Riot Control Brigade when Shao Kahn began taking souls. He finds himself the lone survivor of a city once populated by millions.

The ninja returns — unmasked. Betrayed by his own clan, the Lin Kuei, he broke sacred codes of honor by leaving his clan and is marked for death. But unlike the ninja of old, his pursuers come as machines. He must not only defend himself against the Outworld menace, but he must also elude his soulless assassins.