WARNING:This series contains scenes of mild violence murder. Viewer discretion is advised!
Rider Time: Kamen Rider Decade VS Zi-O -Decade Mansion's Death Game- (RIDER TIME 仮面ライダーディケイド VS ジオウ -ディケイド館のデス・ゲーム-,Raida Taimu: Kamen Raidā Dikeido Tai Ji-Ō -Dikeido-Kan no Desu Gēmu-) is the third installment of the Kamen Rider Zi-O Spin-off series that focuses on Tsukasa Kadoya.
Various people with different backgrounds, including an unusual Sougo Tokiwa, are waking up finding themselves stranded in a house on an isolated island and forced to participate in a death game by a mysterious masked clown. After each round, a loser is killed by a monster emerging from mirrors. As the body count gradually increases, a strange passerby suddenly appears.
After a trailer that contained a Tsukasa Kadoya subliminal message premiered on October 31st, it was announced at the end of An episode of Kamen Rider Blades (a Kamen Rider Saber spin-off episode on TELASA), that a new collaboration between TELASA and Toei Tokusatsu Fan Club will be new episodes for Kamen Rider Zi-O's spin-off, Rider Time. They both premiered on February 9, 2021, but this one will air on TTFC while the other on TELASA.