Power Rangers Heroes

In 2077 AD, countries fought for survival resources, which eventually turned into a nuclear war that destroyed human civilization. Fifty years later, in the post-war desert world, a mysterious man appeared out of nowhere. No one knew his origins - even he himself had no clue. Because he lost his memory, but he clearly remembered three things in his mind. First: My name is Emperor Shitian. Second: I am being hunted. Third: There is a very important thing that needs to be done by yourself, otherwise humans will become extinct.