The experts of the Mystic Sect all had powerful backers, and they were the most formidable forces in the Prehistoric World.
For the future of the Mystic Sect, they did everything they could to thwart the rise of Buddhism. Even though the hidden master of the Mystic Sect wouldn't directly support them, he would definitely ensure their safety and prevent them from falling victim to the hands of the saints.
Yes, in a sense, Jiang Chen was a disciple of the Mystic Sect, and a high-ranking one at that. Therefore, it was also his duty to prevent the spread of Buddhism.
Empress Nuwa, the youngest direct disciple of Honjan Daizu, embodied the orthodox lineage of the Mystic Sect, just as the Three Pure Ones do. The Human Race, as a species created by Empress Nuwa, inherently carried a part of the destiny of the orthodox lineage of the Mystic Sect.
