Dr. Noroi is the true leader of the Government of Darkness and the pilot of King Dark. He was originally friend of Keitaro Jin in Jouhoku University as teacher, before at some point either joining or founding G.O.D. and plotting to take over the world.
He is revealed to be the leader of G.O.D. after King Dark's defeated before stabbed by X's Ridol Whip and apparently dying in King Dark's destruction along with Scorpion-Geronimo Jr..
- Though King Dark later appeared in Kamen Rider Decade: All Riders vs. Dai-Shocker and OOO, Den-O, All Riders: Let's Go Kamen Riders, his true nature as a giant robot controlled by Dr. Noroi is not seen.
- Unlike the Great Leader of Gel-Shocker and the Great Leader of Destron, Dr. Noroi, voiced by Fumio Wada rather than Goro Naya, would appear to be a different entity than the Great Leader. However, in Kamen Rider Stronger, as the Great Boss of Delza Army, the Great Leader claimed to be responsible for creating the Government of Darkness as well as Geddon (led by Ten-Faced Demon Gorgos) of Kamen Rider Amazon.