Kamen Rider Zi-O

From the introduction: In the year 2068, the entirety of planet Earth has become a barely habitable hell. More than half of humanity has died to the reign of terror led by an all-powerful despot: Kamen Rider Oma Zi-Oh. A last ditch assault led by a Resistance of ordinary people is utterly crushed by his overwhelming power. This tyrant loudly proclaims they never had any chance of victory, for he was born to be king. The Resistance is utterly slaughtered, and what little hope there was of overthrowing the Demon King with a stranglehold over Time itself is lost.