After the Righteous Dao Alliance and the Six Devil Dao Sects had discovered a withered ancient Profound Goddess's Palm near the Moulan Plains, they made a plan to acquire the Spirit Well Tree. Du Dong was one of cultivators, who infiltrated the three sects. He was to give orders for the Righteous and Devil Dao to cooperate.
Sword Trial Assembly
Along with others disciples, Du Dong travelled to the Hundred Possibilities Sect, where the Sword Trial Assembly took place. Du Dong won enough to take 10th place. Then the top 10 cultivators were taken to the Spirit Well Tree's cave. On their way, they met early Nascent Soul cultivator boy Lan, who exposed cultivator Bai being a spy from the Righteous Dao Alliance's Overwhelming Pavilion and managed to subdue him.
As they were waiting in the Spirit Well Tree's cave, forces from the Six Devil Dao Sects, including Old Devil Blaze and Scholar Golden Mirror, attacked. Seniors went to battle and the 10 junior cultivators were taken away. Cultivator Bai escaped and joined Du Dong. After activating the Greater Sifting Mirage Technique, Du Dong returned to his cultivation level of mid Core Formation stage. Then he killed Han Li by piercing his chest with a hand, because he considered him odd. He couldn't see through Silvermoon's Fox Enrapturing Arts. They didn't kill others, because one of them was a close descendant of Eccentric Heavenvenge.
In the Spirit Well Tree's cave, they joined Old man Wei from Drifting Cloud Sect, who actually was from Heavenly Fiend Sect. Old man Wei, feeling reluctant to part away with Drifting Cloud Sect, which he was found of, only offered the Wine Nectar to take instead of whole Spirit Well Tree. As Du Dong agreed, cultivators of three sects appeared revealing they knew about their plot. But then Truelord Heavenfiend possessed Old man Wei and clashed with Child Fire Dragon and others. This allowed Du Dong escape with the Wine Nectar. Cultivator Bai was killed.
Du Dong was at mid Core Formation stage.