The Great Leader
Although they did not know it at the time each of the (TV) Kamen Riders (1 through Black RX) battled organizations founded by the same evil being, a creature known as "Dai Shuryou", Great Leader or Great Boss. This being could be killed only to come back to life in another form.
In Kamen Rider the voice of Shocker and Gel Shocker: Naya, Gor�. Appeared as man shapped figure hiding his face behind several masks.
In Kamen Rider V3 the voice of Destron: Naya, Goro. Appears as a person known as High Destron" but when V3 meets High Destron he appears to be nothing more than a skeleton.
In Kamen Rider X the leader of the Government of Darkness hides behind the front of a giant robot called King Dark. King Dark is controlled by a mad scientist named Dr. Norai. There is no visible connection between this Dr. Norai and the Great Leader, but see below.
In Kamen Rider Amazon Naya, Goro was the narrator. Gedon appears to be lead by Gorgos, the 10-Faced Demon. The Garanda Empire seems to be led by Emperor Zero, but see below.
In Kamen Rider Stronger the voice of Satan Bug (Black Satan) and Delza Army General: Naya, Gor�. The Delza Army General is a giant stone robot, controled by a giant alien brain, which claims to be responsible for all of the evil groups, from Shocker through the Delza Army. So even when his voice was not heared the Great Leader was operating behind the scenes after all.
In New Kamen Rider (Skyrider) the voice of Neoshocker: Naya, Goro.
The Great Leader appears as a giant dragon which is destroyed by the combined efforts of all 8 Kamen Riders.
This appeared to finally be the end of the Great Leader because Kamen Rider Super 1 featured two new evil groups each with its own leader.
However, in the tv special Kamen Rider #10'S Birth! Riders Come Together, all nine Kamen Riders, including Amazon and Super 1, join a new Kamen Rider, Kamen Rider ZX in fighting a new group, Badan. Badan's chief officer Ambassador Darkness boasts that Badan will succeed where all of the previous groups failed. Ambassdor Darkness is the twin brother of Shocker's Ambassador Hell. After Darkness Ambassador is killed a giant skull with glowing eyes appears in the sky and the a familar, haunting voice (Naya, Gor�) is heard laughing at the Kamen Riders. Once again, the Great Leader is working behind the scenes.
There appears to be no connection between the evil Gorgom in Kamen Rider Black and the Great Leader. The giant alien heart which leads Gorgom is voiced by Watabe, Takeshi NOT Naya, Gor�. However, there was no apparent connection between Government of Darkness, Geddon, the Garanda Empire, Dogma Kingdom, Jin Dogma and the Great Leader, altough it seems that he was secretly behind them so could he not have been somehow responsible for Gorgom after all?
In Kamen Rider Black RX the voice of Grand Lord Crisis: Naya, Goro.
Grand Lord Crisis was a giant alien head with no body. Grand Lord Crisis also claimed this would not be the last the Kamen Riders would see of him. We do not know for sure that Grand Lord Crisis was the Great Leader, once again, but it seems likely.
The real Naya, Gor�
Sadly the movies Shin Kamen Rider, Kamen Rider ZO, Kamen Rider J and the television series Kamen Rider Kuuga do not mention the Great Leader. (Neither do the fake Kamen Rider series that came later). So it would appear with the defeat of Grand Lord Crisis, by Kamen Rider Black RX, that the evil force that plagued each of the Kamen Riders has finally been vanquished.
Badan Leader photo provided by Basri Ispandi author of Dedicated To Black.
Naya, Gor� photo provided by Takumi