According to ancient texts written by his loyal disciples, the Choujintei brought humans from different worlds to colonize a lifeless planet they would call Ankoku Nui. However, evil creatures called "Matoran" rose up to terrorize the populace, so Dai-Shinra was established to defend humankind from the Matoran attacks.
Some years later, a mysterious plague supposedly developed by the Matoran broke out, killing randomly selected denizens at 17 years of age, and the Choujintei promised immunization to those who signed up with Dai-Shinra's military police to help eradicate the Matoran. This immunization process involved human experimentation, however, leaving many refusing to join the soldiery voluntarily and questioning why the Choujintei could not just exterminate all the Matoran himself, despite his godlike power, instead of sacrificing/risking the lives of others. Dai-Shinra continued killing Matoran without any casualties, eventually paying no mind to the Matorans' refusal to fight back against the humans who now appeared invincible compared to them, which only raised more questions and led to protests against the the Choujintei's way of running things.
Centuries later, a Matoran calling himself Crono, who acts more docile than those of his kind exterminated over the past (near) millennium and believes the Choujintei is tied somehow to the corrupt Brotherhood of Makuta, makes contact with Gainaz and Zonan. The Choujintei becomes convinced Gainaz and Zonan have turned traitor and orders Hairo Washi, the most decorated Dai-Shinra soldier at the time, to bring the teens back to him for punishment and to kill Crono.
At the Great Temple, Crono tells Gainaz and Zonan that the Matoran inhabited the planet long before humans came and are not truly evil. The Choujintei murdered the majority of them, turned the survivors into Shadow Matoran, and misrepresented them as naturally hostile lifeforms, which is why nearly all the Shadow Matoran hunted down did not put up enough of a fight to kill even a single human, and even begged for mercy. Crono also says he believes the Choujintei himself caused the outbreak that he claimed the Shadow Matoran unleashed, to justify his forced drafting of new recruits into Dai-Shinra and the horrific experiments performed on them, but Crono has yet to find credible proof of this. They do, however, find a clue to the location on the outbreak's origin, pointing them to Onu-Kuro, where they eventually discover the Fatal Age Terminator Engine.
Shortly after Hairo catches up to Crono's group, the Choujintei steps in and incapacitates the Matoran, demanding his subordinate to shoot Gainaz and Zonan for their defiance. When Hairo iterates that this would contradict his earlier command to bring them back alive, the God-King impales his servant's thigh into the ground and forces him to watch Gainaz and Zonan be tortured. When Crono recovers and reveals that the Choujintei is actually Scryptorek, Hairo turns on his master and shoots him before he can use the Mask of Time, to keep the Makuta from abusing it. The false God-King furiously kills Hairo for his betrayal, but in his blind fury, neglected to retrieve the mask of time, which had been seized by Crono when he wasn't looking. Crono becomes Jikanmu and gravely injures the God-King, smashing his mask and ripping off his left wing, before destroying the Fatal Age Terminator Engine and then finally exposing Scryptorek's crimes against the planet to the people.
See also: Scryptorek/Personality
"You're no God-King! You're not even a Makuta! You're the devil himself!" - Crono to Choujintei
On the outside, the Choujintei paints himself as a harsh, amoral ruler who prioritized his kingdom over the individuals living in it, but nonetheless remains loyal to the well-being of Ankoku Nui. He is also very dogmatic, stressing passionately the importance of killing "infidel" races and compromising one's personal moral code for the good of the universe, if not outright threatening those who doubt his credibility. The Choujintei is very strict with Hairo Washi, despite his many accomplishments and near complete subordination, often pushing him to be more ruthless and not let even his attachment to Gainaz stand in the way of his duties.
On the inside, however, he is actually a spiteful, virulent, selfish, bullheaded, heartless tyrant and a fear mongering hypocrite who shows no love or concern for individual lives and willingly plunders the planet's life force, not even bothering to understand the Lifestream in it's entirety; in fact, he firmly believes that even if Ankoku Nui does die from exhaustion of it's Mako Energy, the blame would lie entirely on those who did not worship him devotedly enough, and they would be left to die while he searches for a new world to conquer and repopulate. If anyone utters the word "Makuta", which he has declared an extremely taboo, vulgar word among the people of Ankoku Nui in order to keep his true nature hidden, the Choujintei will label the speaker as an abhorrent "blasphemer" trying to discredit him, just like the Shadow Matoran who are actually trying to expose his lies to the humans, not attacking them or killing the planet as the God-King falsely accuses them of doing.
He is also especially cruel to Gainaz and Zonan, his own "children", seeing them as failed experiments and not even offering them a choice to come back to his side and be granted some degree of amnesty, or suffer horribly and then likely die for their defiance. He just tortured them without an ounce of sympathy or regret, and cruelly eviscerated and killed his own general in a sadistic blood-rage, expressing a complete inability to control his anger which ironically led to the creation of the very being whose existence Scryptorek tried so tirelessly to prevent.
- "Submit and be saved, or defy and be damned!"
- "Fright makes right!"
- "The humans must learn to fear and obey me as a child would his own father, whether they like it or not!"
- "You deceived and lied to your legal guardian! You sided with a fugitive who desires the complete destruction of our way of life!"
- "Now sit there and watch what happens to anyone who disobeys me!!"
Choujintei (超神皇) literally means "Super God Emperor" in Japanese, but it officially translates to "Great God-King" in the context of the English voice track.
- Though the Choujintei appeared publicly under the guise of an armored being mostly resembling Somnus Lucis Caelum's Lucii form, his helmet resembles an Okotan Protector Mask fused on top of the Kanohi Vahi, thus the helmet may actually be a Legendary Kanohi Mask with a yet unidentified or dormant power, as proven with the revelation that Scryptorek is the Choujintei.
- The mask's name was recently revealed to be the Kanohi Farusei, the Mask of False Divinity.
- In a deliberate parallel to Somnus, some accounts present the Choujintei as a wise, heroic king who strove for the greater good, even if at least some of his methods are viewed as unethical by others, while other sources, such as Crono, rightfully decry him as a deceitful, ruthless tyrant who cares nothing for his subjects. These conflicting (storywise) views, and Crono's successful efforts to uncover the truth are collectively an allegory of GokaiWhite's recently confirmed theory that Somnus (as well as the Astral God King Bahamut) is actually a much larger scope villain in Final Fantasy XV, than Ardyn and Ifrit, and Gokai's condemnation of the idea of history being written by the winners.
- In contrast, however, Somnus chose to redeem himself of his terrible actions and blind devotion to the corrupt Bahamut (in the FFXV universe's overall ending in Dawn of the Future), while Scryptorek continued his atrocities to the very end of his existence.
- Scryptorek's God-King form is symbolically analogous to Somnus' negative traits, while his true form, and to an extent, Kardahamut, is analogous Bahamut's megalomaniacal demeanor.
- Despite having a different (english) voice actor to conceal his true identity, the Choujintei was still voiced by the same person as Scryptorek in the japanese version, but with a more formal speech pattern.