The old saying about the agreement when conferring immortality is that once the emperor and his courtiers come, these earthly immortals are no exception and must also be governed by the "Human Emperor". Moreover, if these spirits want to "enlighten", they need someone's enlightenment and sealing, and the best.
Although the Northeast Dragon Qi-blessed Ma Immortals are not earthly immortals, they are still a group of spirits and need external help to practice. The best external force is nothing more than Feng Shui, and the best Feng Shui is undoubtedly Dragon Qi. The last dynasty of China was the Qing Dynasty.
Shanhaiguan Pass Shanhaiguan is a barrier that isolates the Northeast and Guanli. In addition to its military use, it is also a pass for those ghosts and spirits.