Oma Zi-O

"You fools could never defeat me. And do you know why? Because I was born to be king!"

- Oma Zi-O boasting about himself.

Oma Zi-O, also referred to as the Demon King, is the ruler of Earth's civilization in the future and the overarching antagonist of Kamen Rider Zi-O.

He is the apparent future self of the titular Kamen Rider Zi-O, Sougo Tokiwa, who achieved a nigh-omnipotent status in the future and became the absolute ruler of all of humanity in the future.

History
In the future, Oma Zi-O used his vast powers and time manipulation to subjugate humanity in the future. A resistance soon arose to oppose him, but Oma Zi-O easily suppressed them. In the first episode, he is seen using his powers to fight them off before boasting of the fact that he was "born to be king".

Trivia

 * His name can alternatively be spelled as "Ohma Zi-O" with the first word being an anagram for "Maoh" which in Japanese means "Demon King".