Halfway there, the Nine Heavens Exquisite Pagoda within Su Shi'er's body suddenly shook violently.
The sudden change made Su Shi'er halt at once.
"Strange, why won't the Nine Heavens Exquisite Pagoda stop shaking?"
Swiftly taking out the pagoda, Su Shi'er frowned slightly.
After a brief hesitation, he left the Half-step Spirit Severing stage puppet outside on guard while he sat cross-legged in the underground space and sent a wisp of divine sense into the Small world space within the Nine Heavens Exquisite Pagoda.
Under the sweep of his divine sense, the scene within the Nine Heavens Exquisite Pagoda's Small world space immediately appeared in his mind.
At this moment, with the emergence of a sixth-grade Spirit Vein, the pagoda's world space had become incomparably rich in spiritual qi.
A Spirit Vein of this grade was enough to affect the Heaven and Earth Spiritual Qi across an entire sect's territory.
A sect's domain could span several dozen li at its smallest, or several hundred li at its largest.
By comparison, his pagoda space only covered ten thousand zhang in every direction. The spiritual qi emitted by the Spirit Vein gathered within this cramped space, naturally becoming even denser and more abundant.
Although a small amount of spiritual qi leaked away through fissures along the edge of the space, compared with the rate at which the sixth-grade Spirit Vein released spiritual qi, it was scarcely worth mentioning.
Su Shi'er was not surprised by this in the least. He had already anticipated it when he used the Nine Heavens Exquisite Pagoda to collect the Spirit Vein.
Nor was the sixth-grade Spirit Vein the cause of the Nine Heavens Exquisite Pagoda's disturbance.
It was the Thunder Essence lurking within, which had previously lain motionless like a dead thing.
Compared to before it refined the