Red Jack and Spades

Someone asked, what is the world? This question is so unexpected that many people cannot give an answer. Until someone said that the world is like a leaf, a flower, a stone, and a grass. This answer is extremely strange, but the person who asked the question still recognized it. Then, he gave his own answer. "This world is a huge glass ball, pure and white. Everything around it is flowing darkness. Even a little bit will pollute it. Therefore, it needs someone to protect her." As a result, the descendants of the person who answered the question before became the group of people who guarded the world in the flowing darkness. They were called the "corner tribe". And those few lines of dialogue are the story of the ancestor of the "Border Tribe" and the great prophet.