Zai Qiu was a member of the Royal Sacred Sect and descendant of the Sacred Emperor. When his younger disciple brother was killed due to inaction by Quinn and Qin Wentian, he sought revenge, slaying Quinn and attempting to kill Qin Wentian. However Mo Qingcheng whipped up a storm which put the battle on an equal playing field and ultimately led to Zai Qiu being defeated after Qin Wentian slew Xia Sheng.
Zai Qiu’s surname was Zai, the surname of the Sacred Emperor. His status wasn’t simply someone of the Core Faction, he was also one of the direct descendents of the Sacred Emperor.
Those surnamed Zai would usually hold high positions in the Royal Sacred Sect and possessed special privileges. If his surname wasn’t Zai, Zai Qiu wouldn’t have dared to be so brazen, acting first without seeking approval. It was because he knew that nobody dared to touch him. Not even the Battle Sword Faction, unless the Battle Sword Faction wanted to use the lives of everyone in their sect to gamble for Zai Qiu’s life.