In the early 20th century, the technology of steam has developed to the highest point.
The Antichrist, who believed in Satan, opened the door to hell by applying the mysterious sciences recorded in the “Jade Directory”. They called the demons to damage everywhere and attempted to rule the human world. Luckily, there was a group of righteous scientists determined to save the world. They took a heart of an ancient devil, which was protected by the church, made it to be the driving force and created “Hellbot” to defend against the threat from hell and stop the evil plans of the Antichrist.