Their first aim was the emperor of the External World Shao Kahn. Before bringing their plans into life, the magicians decide to remove those, who can interfere with their plans. The latter agrees under the condition that he will get eternal youth and immortality. He can do this with the help of another magician, whose name is Shang Tsung. To do that he needs to places the souls of the dead warriors into the mummies. The magician understands that he can become invincible if he resurrects that army.
As Quan Chi is trying to escape from Scorpio through the portal from Hell, he found an ancient tomb with mummies of invincible army of the King Dragon, the first emperor of the External World.