His true identity is Nobuhiko Akizuki, the stepbrother of Kotaro Minami / Kamen Rider Black, who like him was born on the day of a solar eclipse and kidnapped by the Gorgom cult to be brainwashed into being their messiah. Like Black, Shadow Moon utilizes the King Stone to transform into his Rider form and is armed with a sword, the Satan Saber.
After Gorgom's downfall and his presumed death, Shadow Moon would return in Kamen Rider BLACK RX to finally settle his score with Kotaro.
Shadow Moon later returns as the main antagonist of the movie All Riders Vs Dai-Shocker and a major antagonist in Super Hero Taisen Z.
He was voiced by Masaki Terasoma, and Takahito Horiuchi as Nobuhiko.
Kamen Rider Black
Alongside his best friend and stepbrother, Kotaro Minami, Nobuhiko Akizuki was abducted by Gorgom to become one of their new Century Kings. Kotaro however, managed to escape after he was given a Kingstone, allowing him to transform into Kamen Rider Black. In the process, Kotaro damaged Nobuhiko, forcing him into a deep slumber to recover from his wounds.
Nobuhiko later recovered from his wounds. Upon awakening he assumed leadership over Gorgom. He later went to go fight Kotaro. Shadow Moon attempted to fight his brainwashing and briefly turned back into Nobuhiko, but he was unable to keep fighting due to the Creation King's interference. With nothing to hold him back, Shadow Moon attacked Kotaro and ultimately killed him.
Shadow Moon later engaged in another duel with a revived Kotaro. Kamen Rider Black defeated him by using the Satan Saber to slash his Kingstone. He was last seen in the Gorgom Headquarters as it was exploding.
Kamen Rider Black RX
He returned during his step-brother's fight against the Crisis Empire. Wielding the twin Shadow Sabers created by his Kingstone, he sought revenge against Kotaro. He was finally killed when RX stabbed his Kingstone with the Revolcane. As he dies, he informs Kotaro of the Crisis Empire's plans to cause a volcano to erupt as he rescues kidnapped children trapped within the area.
Kamen Rider Decade: All Riders Vs. Dai Shocker
- Main article: Nobuhiko Tsukikage
Shadow Moon returns again, this time as Nobuhiko Tsukikage, a butler to the Kadoya family and an alternate reality version of Nobuhiko Azikuzi. While Tsukasa was away, he took care of Sayo Kadoya. When Tsukasa returns and reassumes leadership of Dai-Shocker, he usurps him and convinces Sayo to become High Priestess Bishium.
However, Decade later joined up with the other Kamen Riders and they all attacked the forces of Dai-Shocker. Nobuhiko transformed into Shadow Moon and fought Decade and Kuuga, but was defeated and slammed into the wall by Kamen Rider Double. He was then finished off by the Kamen Riders kicking him at the same time in an "All Rider Kick".
Kamen Rider x Super Sentai: Super Hero Taisen
Shadow Moon appears as one of the members of the newly revived Dai-Shocker led once again by Tsukasa Kadoya as the Great Leader of Dai-Shocker and formed to hunt down the Super Sentai in response to Dai-Zangyack's targeting of the Kamen Riders. After Dai-Shocker and Dai-Zangyack reveal their alliance and betray their figureheads, Shadow Moon took part in the massive battle between the combined forces of the Kamen Riders and Super Sentai and the Shocker-Zangyack Alliance.
Kamen Rider x Super Sentai x Space Sheriff x Super Hero Taisen Z
Shadow Moon returns once again as one of the main antagonists of this movie alongside Space Reider, he leading a new incarnation of Shocker called Space Shocker to conquer the universe by wreaking havoc all across it with magic. Secretly, he is working with Reider of the Space Crime Syndicate Madou to revive Demon King Psycho by capturing Psycholon, a robot that houses part of Psycho's soul.
During the battle at the Genmu Castle between the combined Kamen Riders, Super Sentai and Space Sheriffs, Shadow Moon is defeated by the Kyoryugers.