In Kamen Rider Zi-O Ep. 40: 2017- The Grand Climax, after obtaining the Den-O Ride Watch, the new Grand Zi-O Ride Watch suddenly formed in Sougo's hands! A Ride Watch that contains the strongest of powers: the combined strength of all the past Heisei Riders! However, after Sakurai Yuuto and Deneb intervened in the timeline,