Hua Wuji became the first outer sect elder of Dan Shen Sect.
Suddenly transitioning from an outsider to a member of Dan Shen Sect, naturally future interactions would be vastly different.
The reason Ye Qiu agreed was partly because he believed Dan Shen Sect needed to develop and it was best for things not to be directly handled by him. Moreover, Hua Wuji had this intention, and since their relationship was quite good, becoming part of the same sect wouldn't be a bad thing.
Secondly, Hua Wuji was from the Hua family. Even though his relationship with the family wasn't great, his becoming an elder of Dan Shen Sect would inevitably link him with the Hua family in outsiders' eyes, and he has a talented sister in Piaomiao Sect, Hua Wuhun. Thus, relationships with Piaomiao Sect wouldn't be too strained.
