Great Dao Primordial Spirit was precisely Su Yun's trump card.
Back then, Yingying had organized the ancient universe's classics and translated them into modern script. Su Yun, Yu Qingluo, and Chai Chuxi had studied the cultivation manuals of the Supreme Hall and gained an extremely deep understanding of the Great Dao Primordial Spirit.
The people of the Immortal Dao Universe had inherited Emperor Chaos's Spiritual Nature and lacked the heavenly and earthly souls. Thus, they could not cultivate the Supreme Hall's manuals without revisions and deletions before those arts could be passed down.
However, relying on their understanding of the Great Dao Primordial Spirit and combining the characteristics of Dust Curtain Sky and the immortal cities, Su Yun and Yu Qingluo had created a method that could temporarily grant one a Great Dao Primordial Spirit.
This was the Great Dao Primordial Spirit Su Yun was currently wielding!
Like Dust Curtain Sky, the immortal cities consisted of countless modules that could be assembled into different forms. Thus, the method Su Yun and Yu Qingluo created used Dust Curtain Sky as the earthly soul and the immortal cities as the heavenly soul. With the three souls united, they formed the shape of a Great Dao Primordial Spirit!
The Great Dao Primordial Spirit form had been an ultimate art Su Yun and Yu Qingluo created to contend against beings such as Di Feng and the Evil Emperor. Yet they had never expected it to be exposed ahead of time because of an obscure Grand Protector, Shang Jinge.
Had Shang Jinge not been nearly impossible to solve, Su Yun would not have revealed this reserve so soon.
Shang Jinge raised his head and saw the towering Great Dao Primordial Spirit behind Su Yun. An incredulous look appeared on his face. The six immortal cities