Generalissimo of Badan

The Generalissimo of Badan: The giant skull which appeared after Ambassador Darkness's death. It disappeared sneering at the ten Riders. Dr. Kaidō said that it was the energy of an evil spirit.

Kamen Rider Spirits
In the manga, Kamen Rider Spirits, the leader is identified as Great Leader JUDO, JUDO has a Kamen Rider form called Susanoo, a golden version of ZX with the ability to transform into nine Shōwa Kamen Riders. He has his own language, which he can telepathically compel others to understand.