Reider, also known as Strategist Reider and later Space Reider, is a Shinigami sorcerer from the underworld serving as a high-ranking member of the Space Crime Syndicate Madou and a major villain of Space Sheriff Sharivan. He sought to take over Madou after infiltrating their ranks. He later returns as the secondary antagonist of Kamen Rider x Super Sentai x Space Sheriff: Super Hero Taisen Z, where he is revived and works alongside Space Shocker, led by Shadow Moon, to bring back Demon King Psycho.
He was portrayed by Mitsuo Ando, who is best known for playing the Black Cross Führer in Himitsu Sentai Gorenger and Professor Gill in Android Kikaider. When he returns in Super Hero Taisen Z, he is played by Hirotaro Honda.
Space Sheriff Sharivan
Originating from the Death Spirit World, Reider arrived in the Genmu Castle after the numerous failures of Madou's executives to defeat Sharivan, and offered to deal with the Space Sheriff in exchange for a high position in the Madou's ranks. Demon King Psycho agreed and Reider went out to face Sharivan, using his illusionary powers to torment Sharivan with visions of his death, severely dampening the Space Sheriff's ability to fight. Psycho was impressed and upon Reider's return to Genmu Castle appointed him the new second-in-command of Madou, much to Doctor Polter and General Gyrer's outrage. However, Sharivan was able to overcome Reider's conjurings and fight off the sorcerer, leading Psycho to give Polter back her position as high commander and suspend Reider from entering battle for his failure.
To regain his position, Reider sought to play the two other Madou executives against each other. Through his mystical abilities, Reider convinced Gyrer that he would make a better army commander than Polter and gave him ambitions of usurping her, while at the same time making Polter paranoid that Gyrer was trying to overthrow her. After Gyrer got drunk and stormed Psycho's throne room to confront Polter, Gyrer was thrown in the Madou dungeon by Psycho. Fearing that Gyrer could still come after her, Polter sent Miss Demon 1 and 2 to murder Gyrer in his sleep. Gyrer anticipated this and fought them off once they entered his cell before going to confront Polter again. It was at that point that Demon King Psycho, tiring of Gyrer's antics, turned him into a statue to hold up the throne of Madou, where his chosen successor would sit.
Reider immediately began seeking to be the one to sit in the throne, competing with Polter to do so. After Psycho gave Reider a chance to redeem himself by using his mystic powers to keep Sharivan distracted from their secret base on Earth, Reider took it and was able to win back his spot in Madou. To further sabotage Polter, Reider tormented her with dreams of past Makai Beasts that had been slain by Sharivan. As Polter began seeking to alleviate these night terrors, Reider advised her to construct an alter and sacrifice children to appease the spirits of the dead Beasts. Gyrer also later was freed from holding up the Madou throne, giving Reider another rival.
With the discovery that the Iga Crystal was on Earth, Demon King Psycho declared that whoever brought the crystal to him first would be his successor. To locate the Crystal's hidden location, Reider summoned his ally from the underworld, Great King Gamagon, and used his sensitivity to light to track down the Crystal's hiding place. Despite Polter and Gyrer's best efforts, Reider would ultimately be the one to bring the Iga Crystal to Psycho while Gyrer died holding off Sharivan, leading Reider to be anointed by the Demon King as his successor.
However, Psycho caught on to Reider's ambitions of overthrowing him and tasked the sorcerer with eliminating Sharivan to get him out of the way. Reider realized that Psycho was on to him and told the Demon King that he would defeat Sharivan using Gamagon, while secretly plotting to finally strike against the Demon King. As he left to go find Sharivan, Reider took notice that he was being spied on by Miss Demon 2 and had Gamagon devour her. While Gamagon fought Sharivan, Reider stormed the Genmu Castle and struck down Psycho as he sat in his throne, seemingly killing him. Reider then ordered Polter and Miss Demon 1 to finish creating the machine to extract the Iga Crystal's power. However, it was at that point that a mysterious bald man suddenly showed up in Genmu Castle. The man revealed himself as Psychorror, the medium body of Psycho, and used his powers to revive Psycho before destroying Reider.
Kamen Rider × Super Sentai × Space Sheriff: Super Hero Taisen Z
Reider was later resurrected for the purpose of reviving Psycho. To this end, he used his magic to revive Shocker as "Space Shocker", forming a pact with an army of past foes of the Kamen Riders led by Shadow Moon. The forces of Space Shocker sought to capture Psycholon, who is a fragment of Psycho's consciousness necessary for his revival. Eventually, the Kamen Riders, Super Sentai and Space Sheriffs caught on to the Madou-Space Shocker alliance's plans and launched an attack on Space Shocker Castle to stop them. Reider was destroyed by Kamen Rider Wizard and the Zyuden Sentai Kyoryuger, but was later resurrected by Psycho in the form of Space Reider alongside numerous Super Sentai Villains. As reinforcements arrived to help deal with Psycho and Reider's revived army, Reider is destroyed for good by Kyoryu Gold and Kamen Rider Beast.
Space Crime Syndicate Madou