The King didn't intervene in the battle between the Night Mountain Sect and the Black Lake Sect.
The Night Mountain Sect claimed that these disciples had invaded their territory. Thus, the sect was now punishing these disciples for this crime.
Meanwhile, the Black Lake Sect claimed that the warriors of the Night Mountain Sect were lying. They had secretly entered the Black Lake Sect and kidnapped their genius disciples.
The reputation of the Black Lake Sect was much better than the Night Mountain Sect in the martial world. Many people felt inclined to agree on the Black Lake Sect's side.
The Night Mountain Sect was considered to utilize evil techniques. In reality, the Night Mountain Sect's techniques had been created after observing the demonic techniques.