A resistance soon arose to oppose him, but Oma Zi-O easily suppressed them. On a day known as the 'Day of Oma', Oma Zi-O conquered the world with seven machines called Dai Mazines, using his vast powers and time manipulation to wipe out half of humanity and subjugate the rest.

Secretly, Sougo's rise to power was manipulated by Kamen Rider Barlckxs and the Quartzer. When Sougo was young he was abducted along with several other children on a bus trip and had Sworz whisper in his ear that he would one day become king. 1.7 Rider Time: Kamen Rider Zi-O VS Decade.1.6 Rider Time: Kamen Rider Decade VS Zi-O.1.5 Final Battle and Conversation with his younger self.As old Sougo Tokiwa, he was portrayed by Seiji Takaiwa, the suit actor who is known for playing the primary roles in suits except Kuuga and Hibiki. He was voiced by Rikiya Koyama, who also played Kagetane Hiruko, Giovanni in Pokémon Origins, Kiritsugu Emiya, Kamen Rider Bujin Gaim in Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle and Paradox Roidmude in Kamen Rider Drive: Surprise Future. He later returns as the main antagonist in both Rider Time: Kamen Rider Zi-O VS Decade and Rider Time: Kamen Rider Decade VS Zi-O. As others travel back in time to stop his rise to power, Oma Zi-O sends his prophet Woz to the year 2018 to ensure his past self completes his journey into the Demon King. In his rise to power, Oma Zi-O devastated the world into ruins and wiped out half the population. He is the reason that most of characters travel back in time, either in order to stop him by eliminating Zi-O or preventing Sougo from becoming Zi-O, like Geiz, Tsukuyomi and White Woz, or coronating a person other than Sougo to be Oma Zi-O, like the Time Jackers.

He is the future self of Sougo Tokiwa, who achieved a nigh-omnipotent status in the future and rules the Earth in the year 2068 as its king. Oma Zi-O, born Sougo Tokiwa, also known as the Demon King and formerly known as Kamen Rider Zi-O, is the titular central antagonist/protagonist of Kamen Rider Zi-O. And do you know why? Because I was born to be king!

Kamen rider zi o