No, One Piece is created by Eiichiro Oda. He might have a team of assistants to help with various aspects, but the main creative vision and story come from him.
I'm not sure about the exact main theme as I haven't read it. But it could potentially be about the significance of a single night in changing a person's life or perspective.
The only god in the night was Haotian. Haotian was the patron saint of this world and the only god in the drama. She lived in the Divine Kingdom in the sky and was worshipped and worshipped by the people of Taoism and the West-Hill Divine Palace. Haotian had endless time and eternal power. He had been silently protecting and maintaining the rules of the human world. Every once in a while, she would launch an Eternal Night to eliminate the existence that threatened her in the human world and create the next era and civilization. Although Haotian was worshipped by countless people, she was also resisted and suspected by humans. In the end, Haotian found that humans had grown to the point where they no longer needed her protection, so she transformed into a human and lived in peace with humans.
The only god in the night was Haotian. Haotian was the patron saint in the play and the only god in the world. She lived in the divine kingdom in the sky and was worshipped and worshipped by countless people. Haotian existed to protect humans, but she would not protect humans for free. Instead, she would collect protection fees from time to time. With the development and evolution of human beings, they began to express their dissatisfaction with Haotian's behavior and resist. In the end, Haotian found that humans had grown to the point where they did not need her protection, so she transformed into a human and lived in peace with humans. Haotian's story was the process of deification.
Well, it depends on your perspective. Some might think it's the only one, but others may have found other manga with similar themes that they love just as much.
The TV series "Night Son of Heaven" had a total of 48 episodes, and it had yet to be announced whether there would be a second episode. The play was a youth fantasy drama produced by China's TV production company, Beijing Light Media Co., Ltd., which was first broadcasted on July 12,2018. The play told the story of a group of young people who grew up in a fantasy world. Although the drama was very popular, there was no official confirmation of whether there would be a second one.