Upon hearing Fusang's words, Jiang Chen fully understood why he felt a mysterious premonition in the Eastern Sea's boiling valley the day he refined the original source of the nine Golden Crows.
So this is the root cause!
The treasure sealed by Taiyi in the boiling valley turned out to be the original source of the East Sea Lord.
In the Ancient Era, as the Supreme Star, the Sun Star nurtured three Innate Divine Saints. Two of them were within the Sun Star, while the other one resided in the boiling valley of the Eastern Sea.
After refining the remains of the nine Golden Crows, Jiang Chen's original source transformed, thus enabling him to resist the innate order and transform into a top-tier Innate Divine Demon.
However, the power of the nine Golden Crows could only get him this far. If Jiang Chen wanted to further evolve into an Innate Divine Saint, he would need another opportunity.