Kazi ultimately learned the Imperial Sect alongside the Great Noble Families defeated the eight-headed dragon. The merchant-historian discussed the team-up between the Kangxi Emperor and the Eternal Emperor. Both families suffered the most, to the point that the Imperial Sect lost its place among the Big Four.
Indeed, the Big Three was once the Big Four. The Imperial Sovereign Sect had already been established by the Kangxi Emperor's mother and, upon his prophesized appearance and the birth of his children, became truly great. Great enough that, during the Second Heavenly War, the Imperial Sect grew to rival the Big Three.
However, upon losing thirty of his children to several tragedies, the greatest of which was the attack of Yamata-no-Orochi, the level of influence and raw power of the sect sharply declined. See, one son in particular was a prodigy said to be greater than the Kangxi Emperor and was killed during the battle against Yamata-no-Orochi.