Decade's World
The mysterious Dai-Shocker organization is a conglomation of all villain organizations who set into motion a plan to take over all dimensions due to someone providing the means to do so. Their insigna is double-headed version of Shocker's eagle crest, but with the "DCD" written on it that hints at Decade's ties to them. In addition to Doctor Shinigami and Apollo Geist, there are many other members of Dai-Shocker that come from previous Kamen Rider Series. They sent their agents out across the worlds for universal domination.
Nobuhiko Tsukikage / Shadow Moon
Nobuhiko Tsukikage is a butler who takes care of Sayo and convinces her to become Bishium as part of his plan take over Dai-Shocker in the Decade World. Through the Stone of the Moon, Nobuhiko can transform into Shadow Moon. Once he ousts the former leader of Dai-Shocker, Tsukasa Kadoya, Nobuhiko becomes its leader as he leads the group to hunt down every Kamen Rider. In the end, though he overpowers Decade and Kuuga, Shadow Moon is defeated by Double and destroyed by the All Rider Kick.
Ambassador Hell
Ambassador Hell (is an executive member from the terrorist organization Shocker, originally from the World of Kamen Rider and donning a new black armor. He is able to assume the form of the Inhumanoid Garagaranda, a rattlesnake monster. In the final battle, he fights Kamen Rider 1, 2, Kabuto, and Black RX. He is killed when Riders 1 and 2 use a Rider Double Kick on him after being stabbed by Kabuto and impaled by Black RX, he praises Dai-Shocker before finally succumbing to his wounds and dying in a huge explosion.
General Jark
General Jark is a supreme commander from the Crisis Empire from the World of Black RX. He is killed by Diend.
King Dark
King Dark is a giant robot and the mastermind behind the Government Of Darkness (GOD) from the World of X-Rider. He is killed by Decade Complete Form Jumbo Formation.
Dai-Shocker Soldiers
The Dai-Shocker Soldiers (are footsoldiers of Dai-Shocker, resembling the Shocker Soldiers and tending to scream out "Yeee". They are able to assume missile-like forms.
Rider War World
Super Shocker
The evil Super Shocker organization is formed from last remnants of Dai-Shocker, with the destruction of the Nine Worlds and the destruction of Dai-Shocker. In addition to the high ranking members Super Doctor Shinigami and Colonel Zol, other villains from the Kamen Rider Series make up the ranks of Super Shocker. They utilize the Super Crisis Fortress as their base.
Bee Woman
The Inhumanoid Bee Woman was previously a member of Shocker in Kamen Rider, being the one who killed Tackle while a member of Dai-Shocker. She is now one of the high-ranking members of Super Shocker, going after Natsumi until she is mortality wounded by Electro-Wave Human Tackle's Ultra Cyclone. The Bee Woman releases the Neo Organism to make her more powerful, only to be engulfed by it.

Neo Organism
The Neo Organism of Kamen Rider ZO is a pool of living fluid that relies on the very container its dwells in as its life support and create a grotesque Kamen Rider-like incarnation known as Doras. Its personality is extremely childish and somewhat sadistic, though it appears it doesn't realize the true nature of what its doing, referring to its attacking the Kamen Riders as 'playing'. Super Doctor Shinigami seeks to revive the Neo Organism in order to destroy Kamen Rider Decade. But once revived, it is beyond Super Shocker's control as it consumes Bee Woman and creates Doras to fight the Kamen Riders. Though Doras is destroyed by a combined finisher from all the most powerful forms of the Nine World Riders, the Neo Organism takes control of the Super Crisis Fortress until it is destroyed. However, it survives and absorbs the Dummy Dopant to become the inhumanoid Ultimate D before quickly meeting its end through Decade and Double's Triple Extreme Rider Kick.
Super Shocker Soldiers
The Super Shocker Soldiers are remodeled versions of the Dai-Shocker's footsoldiers, resembling the Shocker Soldiers and tending to scream out "Yeee". Like the Dai-Shocker Soldiers they are also able to assume missile-like forms.