After Min Ren became an Immortal Emperor, he and his old general and former Dao Protector Nine Saint Virtuous Paragon formed a pact. If the Nine Saint Demon Gate had a female prime disciple, while the Cleansing Incense Ancient Sect had a male prime disciple, then two Sects would become in-laws.
The Pact was proposed by Nine Saint Virtuous Paragon to strengthen the relationships between the Nine Saint Demon Gate and the Cleansing Incense Ancient Sect. He married his female disciple to the Cleansing Incense Ancient Sect's first Prime Disciple.
Later on the two Sects had in-law relationships several more times.
By the start of the Current Era there has not existed any in-law relationships between the two Sects for a long time. The Cleansing Incense Ancient Sect declined to the point of extinction, while the Nine Saint Demon Gate was still very powerful and finally had a female prime disciple - Li Shuangyan. Thus, the Cleansing Incense Ancient Sect was eager to form in-law relationships with the Gate to get its backing.
However, Li Shuangyan was born with the King Physique, King Life Wheel and Saint Fate Palace, so the Nine Saint Demon Gate naturally had not wanted to marry off a descendant with such an aptitude and potential to a disciple of a declining Sect.
When Li Qiye became the prime disciple of the Cleansing Incense Ancient Sect all of a sudden, the Nine Saint Demon Gate quickly learned about it and immediately sent an invitation to test his abilities for a marriage. Li Qiye was a mortal with extremely poor talent, so the Nine Saint Demon Gate hoped that he would fail the trials and they would get an excuse to cancel the marriage.
The Sect's Elders were more than happy to see it, except for Cao Xiong. He always wanted to become a Sect Master, or at least to push his disciple into this position, but Li Qiye's potential marriage with Li Shuangyan ruined all of his plans and dreams. Cao Xiong went to a meeting with Dong Shenglong, who promised to him the Heavenly Jewel Kingdom's support. Together they tried to kill Li Qiye, but were outplayed and eventually killed.