As the saying goes, once every emperor was a courtier, these immortals were no exception, and they were also ruled by Ren Huang. Moreover, if these geeks want to "become a monk", they need someone's touch, preferably the emperor's.
According to legend, when the goblin met the emperor Qianlong, he asked him to seal the emperor Qianlong. Although Qianlong was blocked for 500 years, they reached an agreement not to allow Ma Xian to cross Shanhaiguan.
Second, the northeast dragon blessing
Although Ma Xian is not a fairy, he is also a group of monsters who need outside help to practice. The best external force is nothing more than feng shui, and the best feng shui is undoubtedly the dragon god. China's last dynasty was the Qing Dynasty, and Long Mai in the Qing Dynasty was in the northeast, so there is no better place to practice than the northeast. And far away from the northeast, without the blessing of the dragon soul, the mana will be weakened.
Third, Shanhaiguan
Shanhaiguan is the barrier between Northeast China and Guanli. In addition to military use, it is also the gateway to those ghosts and gods. At that time, there were tens of thousands of soldiers guarding Shanhaiguan. In order to resist the Qing soldiers, their spirits guarded Shanhaiguan, which naturally frightened the horse fairies.