To tell the truth, the world of mirrors is quite familiar with evil spirit masters. Shrek College may not know that the Holy Spirit Sect is in the Sun Moon Empire, after all, it is too far away.
However, as the ninth level soul teacher and the leader of the Mingde Hall, Mirror Hongchen did know some people of the Holy Spirit Church, otherwise he could not explain that he disclosed the information about the location of the Holy Lady Ma Xiaotao to the people of the Holy Spirit Church in the original book.
Although the mirror world has a general impression of the evil spirit master, for the current Sun Moon Emperor, he needs the power of the evil spirit master. According to the imagination of the Sun Moon Emperor, if the future Sun Moon Empire launches a war against the Douluo Three Kingdoms, the Holy Spirit Sect will be a great help