The Terracotta Warriors are the loyal army of Emperor Han and the supporting major antagonist of The Mummy: Tomb of The Dragon Emperor. Unlike their real world counterpart whom are mere terracotta statues that modeled after the real army of the Emperor in the past, they are the army of the Emperor Han themselves that cursed into terracotta statues.
Because Zi Yuan, who is said to know the secret of immortality, Han sends his henchman, General Ming Guo, to bring her to the palace. When Ming finds her, Both Zi Yuan and Ming Guo immediately fall in love despite the Emperor demands her for himself. After she seemingly casts immortality spell on the Emperor in Sanskrit, a language that he doesn't understand, he has Ming executed and impales her with a dagger for their betrayal. He did it because she loved Ming Guo instead him and his spies has revealed this. However, Zi Yuan (who has foreseen these events) reveals that she actually cast a curse to both Han and his army instead immortality spell. Emperor Han enrages with this revelation, but the curse painfully causes his body emits mud. Fire from nearby candles burns him alive as they were attracted by his body like a magnet, while his army's bodies also emit the same substance. Unlike the Emperor himself, they spontanenously fell into silent and turned into terracotta itself painlessly.
The Emperor (who transforms into a gigantic three-headed dragon) kidnaps Lin, as he flies to his tomb. As he arrived, he raises the Terracotta Army, now aided by General Yang's soldiers. The Emperor announces his plans to conquer the entire world and that once he led his army across the Great Wall, they will be bestowed invincibility. The O'Connells and Zi Yuan pursue the Emperor to the Great Wall, where she sacrifices her and Lin's immortality to revive the workers killed and buried beneath The Great Wall, creating her own undead army. As they revived, a vengeful, revived General Ming, took the leadership of the army. The Army of the Dead, with aid from the group's modern weapons and air support, fights the Terracotta Army. Zi Yuan battles the Emperor, but she is mortally wounded. Despite this, she succeeds in securing the dagger unbeknown by Emperor himself.
Disguised as one of Yang's soldiers at that moment, Alex rescues Lin, who Yang had bound and gagged in a tent under armed guard. The group gather up again, finding a grieving Lin cradling the dying Zi Yuan in her arms. As this is going on, the Emperor transforms into a horned Ogre to get past Zi Yuan's army and goes beneath the Great Wall in order to use his elemental powers to negate Zi Yuan's spell and draw Ming's army back underneath it. Alex interrupts the Emperor, who transforms into an ogre and knocks Alex into a wall. Rick tries to stab the Emperor, but is getting thrown into a lit torch stand for his efforts.
Meanwhile, Evelyn and Lin who keep up with the Emperor, fight with Yang and Choi. They eventually knocking the general onto some moving gears that crush both him and Choi. The dagger the Emperor hurls at Rick misses and strikes a statue, breaking in two. Rick taunts the Emperor, questioning his honor, turning the battle into a more even fist-fight. While Emperor is gaining the upper hand with his taijutsu skills, Alex grabs the dagger's blade and quietly slips into the nearby water, and left a tactic message to his father. Rick takes the dagger's hilt and plunges it into the Emperor's chest while Alex stabs him with the blade's tip from behind, simultaneously piercing the Emperor's heart from both sides and releasing the dagger's curse. The Emperor is consumed from the inside and out by molten lava, resulting in the deaths of him and his army. Ming's army briefly celebrates before finally moving on to a peaceful afterlife.