What exactly are the seven nights of the Black Dragon mentioned in the fifth episode of the Great Wall of Wan Li during the Qin Dynasty?

There was a mention of "Black Dragon and Seven Nights" in the bright moon in Qin Dynasty, which was cited by Han Feizi. It is said that whoever has mastered the secret of the Black Dragon's Seven Nights will have the power to dominate the world. Reese was ordered to investigate whether Han Fei died in prison. But Han Fei's death is still a secret. Sean, the Great Wall of Qin Wanli Mingyue, said: "I heard Han Fei say that this secret is related to Qi, Chu, Yan, Zhao, Wei, Han and Qin." In the 27th episode, Li Si, who was held by Wei Zhao with a sword around his neck, also made it clear: "The seven stars, seven countries and seven secrets, the core of the Black Dragon and Seven Nights, were held by the sole heirs of all countries in the past." The ancients divided the starry sky near the ecliptic into several regions, the most obvious being the high moon. She is a princess of Yan, and her father is a prince of Yan. Her lineage (Moon God of Yin and Yang family said to Yun Zhongjun: Thank you, Lord Dong, I went here to find not only the long-lost box of Yin and Yang family, but also the princess Qianlong who passed on the sacred lineage for thousands of years). Ganlong's lineage identity is enough to be the heir to this secret. The proof is that the moon took off the necklace around her neck and opened the box in the first 12 episode of Wan Li Great Wall. Tian Ming wears a piece of jade around her neck. The ancients divided the starry sky near the ecliptic into several areas, which were called twenty-eight lodges, and connected them with the four elephants according to their directions and seasons. Zhang Heng has a description in Lingxian County: "The black dragon is curled up on the left, the white tiger is fiercer than the right, the rosefinch is fluttering in front, and the turtle is circling behind." Let's introduce their names in combination with their positions in the sky. Dongqi lodge has: horn, health, ground, house, heart, tail and dustpan.