The Secret Organization G.O.D. (G.O.D. 秘密機関 Goddo Himitsu Kikan?), short for the Government of Darkness (暗黒政府 Ankoku Seifu?), is the evil organization that X-Rider battles against. The organization's monsters are based on Greek Mythology and historic or fictional figures.
The Government Of Darkness was a secret society in which opposing countries secretly joined hands and used cyborg kaijin to try and gain world domination.
In an alternate timeline caused by Ankh leaving a O-Medal behind in the year 1971, Shocker achieved its goal of dominion of Japan with the Shocker Greeed. The Government of Darkness, represented by Apollo Geist and King Dark, was among the various organizations that formed a partnership with Shocker. The two of them were among the Shocker leaders who were destroyed when the Great Leader of Shocker transformed into Rock Great Leader.
World of X-Rider
The Government of Darkness also exists in the A.R. World of X-Rider, where it is fought by an alternate X-Rider. As with the original, King Dark is a giant robot and the mastermind behind the Government Of Darkness (GOD), with Apollo Geist as his lieutenant. The Government of Darkness joined Dai-Shocker, a coalition of the evil organizations that were fought by the Kamen Riders. After the Dai-Shocker army was wiped out by a gathering of 25 Kamen Riders after Dai-Shocker started its invasion of the A.R. Worlds, King Dark emerged from the ruins of the Dai-Shocker Castle. Countered by Kamen Rider J summoned by Diend, he was killed by Decade Complete Form Jumbo Formation.
Apollo Geist emerged as the leader of Dai-Shocker, having been revived by the Government of Darkness after being killed by X-Rider. However, his lifespan is short as a result and thus uses the Perfecter to take the life force out of people to augment his own. When the Perfecter is stolen from him by Diend and then destroyed by Decade, Apollo Geist eventually comes up with the plan to marry Yuki, the Fangire Queen, becoming a Fangire as a result. As a result of his transformation, he now becomes Super Apollo Geist with the ability to remove other realities from existence. Using his power to revive the monsters from the Nine Worlds and attempting to make Natsumi his bride after Yuki is destroyed by Decade Complete Form, Super Apollo Geist fights Decade and Diend until help arrives in the form of Hibiki and Kiva. Kiva and Hibiki distract Super Apollo Geist long enough for him to be mortally wounded by Decade Complete Form with Diend's power, Geist swearing that he will "revive as the greatest nuisance in the universe" before he is destroyed.
Apollo Geist reappeared as part of the new Dai-Shocker assembled by Tsukasa to wipe out the Super Sentai, ensuring the survival of the Kamen Riders. After Dai-Shocker's alliance with Dai-Zangyack is revealed, Apollo Geist is once again defeated by Kamen Rider Fourze Magnet States.
- G.O.D. General Commander (GOD総司令 Goddo Sō Shirei?): A mystery man who commands the monsters using various objects with tape recorders which record his commands.
- Apollo Geist (アポロガイスト Aporo Gaisuto?, 8-14): The Chief of Security of G.O.D., armed with the Geist Cutter shield and the Apollo Shot shogun, his human appearance wears a white tuxedo with black gloves until he invokes "Apollo Change" (アポロチェンジ Aporo Chenji?). He has his own Motorcycle with his Apollo Geist logo. His job is to execute any G.O.D member who considered useless. Destroyed himself using his Arm Bomb after he was defeated by X's X Finishing Kick when he tried to trick him by shaking hand.
- Revived Apollo Geist (再生アポロガイスト Saisei Aporo Gaisuto?, 16-21): Revived by two doctors of G.O.D. Armed with the Apollo Magnum bayonet on his right hand, the Geist Cutter shield which causes explosions when throwed into ground, and the small Geist Cutter shield on his left shoulder. He also has ability to turn himself into huge fireball at his final battle against X-Rider. Destroyed by X's X Kick.
- King Dark (キングダーク Kingu Dāku?, 21-35): The leader of G.O.D., he reveals himself after Apollo Geist's destruction, mocking X. Destroyed by a self-destroying function that Dr. Curse started.
- Dr. Noroi (呪博士 Noroi Hakase?, 35): After King Dark's defeat, Dr. Noroi is revealed to be the leader of the Government of Darkness and friend of Keitaro Jin in Jouhoku University as teacher. Destroyed in King Dark's destruction after being stabbed by X's Ridol Whip along with Scorpion-Geronimo Jr.
- G.O.D. Warfare Agents (GOD戦闘工作員 Goddo Sentō Kōsakuin?): Warriors who serve as foot soldiers for the Government of Darkness. Not only do they carry spears, they also wield pistols and machine guns.
The monsters of G.O.D. are split into two groups: