The task log did not elaborate on the exact reason why the players were doing this, but Yu Liang guessed it was for contribution points.
After all, the players' faction objective was to wipe out the Nine Yin Sect members. When the Sect's major figures were busy dealing with the Limpid Ghostman, few players could resist the urge to set upon the Sect members.
I can't control the progress of the major campaign, but I've killed both minor and major figures, and that's a solid reward in contribution points.
Thus, the Sect Members of the Nine Yin Sect became even more infuriated, unable to tolerate the turnaround of these armed forces and attacking the opposition recklessly.
At this point, the two factions could only escalate their conflict, and it erupted with hostility, so much so that they no longer even thought about guarding against the Limpid Ghostman and only concentrated on attacking each other.