Ku Yao was an early Nascent Soul stage Sage of Fire Rite Tribe.
Once another war with Nine Nations Union started, Sage Ku Yao together with Sage Wen and group of spell warriors accompanied Heavenweep, while attacking the Yellow Dragon Mountains at the border of the State of Yu. Facing 4 Nascent Soul cultivators, they decided one on one duel. Sage Ku Yao fought Old man Ma. With Supreme Eight Trigram Diagram he was able to come to a draw against the Sage and his Fire Spirit Flood Dragon. As Heavenweep wanted to fight next, Han Li faced him. Using Heavenflash Devil Arts he grew to about six meters in height and looked like one of the phantoms of the Six Apex Devils Art. Then he got trapped by golden net of Divine Devilbane Lightning. With his body gone, he tried to escape in form of black demon Nascent, but he was burned into ash. Rest of the Moulan troops retreated.
Sage Le led the next attack. 300 Moulan spell warriors were killed in a formation through a trap. Sage Ku Yao led next attack. Sage Wen fought Old man Ma. And Sage Ku Yao faced Senior Lu, together with his Four-Eared Golden Ape artifact spirit, . While they fought, Divine Sage Zhong arrived and killed Senior Lu. Old man Ma lost an arm. Sage Le was relieved. As Han Li was chased away by the Divine Sage, Old man Ma was hunted down by Sage Le.