Yi Nian Yong Heng 3rd Season Ep 4

After Bai Xiaochun merged the four downstream sects to form the Reverse River Sect, he successfully challenged the three midstream sects and established a firm foothold. He was then chosen by the Celestial Being of the Starry Sky Dao Sect in the upstream to be a hostage, thus beginning the third season, the Hostage arc.(Source: Tencent, translated)