During the events of "Kamen Rider × Kamen Rider W & Decade: Movie War 2010", Decade becomes a destructive embodiment of himself known as before he was defeated by Natsumi as Kamen Rider Kiva-la. While in the World of Negatives, Tsukasa acquires the touchscreen cell phone that attach onto the Decadriver, replacing the card slot which is moved to his right hip, to enable Decade to assume his true . In this form, he can manipulate the power of other Riders' final forms, whom he can summon through the K-Touch, for powerful combo attacks. A stronger variation of the form is which has the Kamen Ride Cards of his predecessors' ultimate forms on his armor. During the events of "", Narutaki restores Dai-Shocker and enters an alliance with the Super Sentai villains that formed the Dai-Zangyack. Tsukasa, feigning to resume his role as Dai-Shocker's leader, declares war on the Super Sentai and battled Captain Marvelous of the Gokaigers to an epic standstill before faking their deaths to catch the villains off guard once they reveal their actual plan to take over the world. Tsukasa also appears in the "Kamen Rider Wizard" finale when summoned by the sorcerer Amadum to attack Haruto, only to aid his successor defeat the villain before departing for points unknown. Tsukasa later returns during the events of "Kamen Rider Zi-O" to help change Sougo Tokiwa's destiny to become a hero instead of a tyrant while posing as an enemy. Tsukasa Kadoya is portrayed by . As a child, Tsukasa is portrayed by .  , referred to as by Tsukasa, is a young woman who works at the photo studio under her grandfather, having lived with him since her childhood. . Prior to the series, Natsumi was a member of the or for short, a group of dropouts who got bored with school and wanted to find out their own answers. But they never carry out their intent and return to school, promising to meet again years later. At the start, Natsumi begins to have nightmares of Decade prior to finding Decade's belt and giving it to Tsukasa. Fully aware of world's endangerment, Natsumi decides to accompany Tsukasa on his journey to prevent her dream from coming true. She occasionally keeps Tsukasa in line with the but she had also used the technique on other people such as Yusuke and her grandfather.