The Heavenly Book of Subduing the Dragon

Legend has it that there is a city named Tianlong City, and there is a book in the legend called the Heavenly Book of Subduing the Dragon. There are two books. One is that the Lord of Tianlong City records the construction of the city, and the other is said to be that whoever obtains it will conquer the world. So there are two groups of people, one is fighting, the other is protecting, and there is another group of special people who value love and justice. They have things they want to protect with their lives, and they also have people they want to protect with their lives...