At some point Sargon has been granted evil powers from the gods, which he uses to his advantages. Sargon was promoted to the ranks of the commander during King Hammurabi's reign. As a general, he supervised the Ancient Games and trained children in order for them to join the Black Scorpion soldier.
During one of his training sessions, a girl named Layla is found is in the midst among the children. When Sargon tries to force her out, her friend Mathayus strikes him with a staff. This results in a fight between him and Mathayus's father Ashur. King Hammurabi orders them to stop fighting and states that Mathayus must complete his training. Sargon swears a vendetta and later, summons a swarm of scorpions to eat Ashur's flesh.
King of Akkad
Years later, Sargon is now the king of Akkad. After Mathayus completes his training, Sargon orders him to execute his brother Noah. Instead, Mathayus frees his brother and attempts to kill Sargon with a spear, which Sargon eludes do to his supernatural powers to telekinetically stop it and redirect it back at Mathayus that dodged it and instead hit one of his guards. Mathayus and his brother flee the city but Noah is killed by a magic arrow fired by Sargon.
Mathayus along with Layla, Pollux's Fellowship and Fung, a lost Chinese man looking for his way home and a Greek poet named Aki. They journey to the Underworld to find the Sword of Damocles, which they steal from the goddess Astarte.
Later Astarte orders Sargon to get the sword back for her, and he asks for more power, which she accepts in exchange for the Ultimate Sacrifice.
The sacrifice Sargon preforms is an event in the arena, which turns out to be a machine that dumps oil into Akkad's water supply. The water begins to flow through the statues in the city, which is then set on fire. During this attack, Mathayus and his allies reach Akkad and find chaos and rioting in the city. Mathayus fights his way through Sargon's guards, and after a heated confrontation, Mathayus and Sargon begin to fight. Sargon realizes Aki's presence and demands the sword, bribing Aki with riches. Aki hands over the sword and leaves. Sargon immediately finds out the sword is a fake. Aki hands the real sword to Mathayus, calling Sargon a "jackass". Sargon reminds Mathayus of his loyalty to the Black Scorpions. Mathayus burns his scorpion tattoo off with his sword. As a result Sargon turns into a giant near to completely invisible scorpion and begins to fight Mathayus again, nearly killing him. Mathayus impales Sargon with the sword, ending his reign once and for all.
Behind the scenes
The historical Sargon of Akkad was the first king of the Akkadian Empire (2334–2279 BC). He did not actually live in the same period as Hammurabi of Babylon who came later (-1810 to 1750 BC). Both existed after the 3067 date when prologue to Mummy returns is set.
There were 8 more Akkadian kings after Sargon, the empire collapsed in 2154. Again long after the events of Mummy Returns prologue.