The Taken for Granite aspect of the Terracotta Warriors. It's not so much the fact that they are this since you see that in many a movie (though it's still quite unsettling), but the process. Just... watching them as they start to liquify from the mouth, the wet clay leaking out as it spreads and takes over their forms, hollowing their bodies out, covering them... Brrr!
And then supernatural jets of fire appear from nowhere and begin heating the clay, turning the emperor and his army into terracotta statues. The whole process seems agonizingly painful, and this also happens to thousands of his men.
The emperor's appearance throughout most of the film; an undead, burnt corpse surrounded by a terracotta shell. His raspy voice and breathing make it sound as if his vocal cords and windpipe are horrifically burned, and he's completely unrecognizable compared to when he was alive. And if his shell is broken for more than a few seconds, it will painfully reform itself around him. See the image above for reference.
Huang, the titular Dragon Emperor himself. Just, everything about him. Long before the film's events, he was a savage warlord who led a brutal conquest of China and took control of the entire country, proclaiming himself emperor of all there was. He then built the great wall using his enslaved enemies as a labor force, burying them beneath it if they died. After wishing to achieve immortality, he enlists the aid of a powerful witch, whom he then decides to make his queen. When his best friend falls in love with her, he has him killed and also tries to kill her merely out of spite, even though he didn't even love her. It makes you wonder what kind of nightmarish world he would've created had he succeeded at the end of the film with his powers.
An early script has its share of moments that make those in the film look tame:
The Emperor's mummification was more graphic as his heart would've been visible through his chest, pumping black blood through his veins that oozes out of his pores. Then his clothes and body would've been covered by molten clay before being superheated and hardened by bright white light beams from inside himself. His army would undergo a similar, if not the same, horrific transformation.
Yang loses an arm to a crocodile as he fights Rick and Evy in an Indian temple. He later gets it replaced with a metallic one able to crush bone.
Instead of restoring his terracotta shell as in the film, the Emperor drains people's life-force to heal himself, much like Imhotep before him. However, the Dragon Emperor takes it a step further and turns his victims into terracotta while he drains them... before smashing them to pieces like porcelain dolls.
Whenever he takes damage as a mummy, maggots, pieces of bone, and fossilized guts trickle through the Emperor's wounds. The avalanche damages him so much that his torso is riddled with cracks, and he loses half of his face, exposing his rotted skull and brain infested with maggots. Upon becoming immortal, the Emperor forms a new brain and eyeball, and skin grafts over his cracked body.
The Emperor is even more ruthless: He sends Zi Yuan to Hamunaptra under the threat of killing her lover if she fails to return within 90 days; however, when she does make it back in time, he gives her Ming's head in a box like a present. When he becomes immortal, the Emperor puts a searing finger to Yang's forehead, makes him kneel, and forces him to pledge his loyalty. He kisses Zi Yuan to spite her and curse her at the same time by turning her and the other immortals in Shangri-La into terracotta statues. Then, as the Emperor takes Lin, he tells her that she will pay for her mother's sins by sharing his bed as his queen in Zi Yuan's place. During the climax, the Emperor punishes Yang for his failure by using his powers to trap him in a giant brass lantern by superheating it around his body.
