The formation had been laid down by him, so he could sense even more clearly that, even with supreme-grade Spirit Stones maintaining it, the spiritual qi within the formation was still draining away at an astonishing rate.
The ten supreme-grade Spirit Stones he had just thrown out would, at most, allow the formation he had set up to endure for a little over ten days.
On average, it would consume nearly one supreme-grade Spirit Stone each day.
This rate of Spirit Stone consumption could not be called terrifying—it could only be called utterly terrifying.
At this moment, he could only secretly rejoice that over the years, he had accumulated quite a substantial fortune in Spirit Stones. On top of that, he had obtained Bai Rufeng's Storage Pouch, allowing him at least a brief chance to catch his breath.
But upon closer calculation, even if every Spirit Stone on him were refined into supreme-grade Spirit Stones using the Heaven and Earth Furnace, there would be no more than a little over three thousand.
Calculated this way, even without using Spirit Stones for cultivation, he could only hold out for around ten years at most.
Though Su Shi'er said nothing, he could not help feeling immense pressure in his heart.
Ten years was not even enough to repair his foundation and heal his wounds, much less... find a way to break the formation.
And once there was insufficient spiritual qi to sustain it, this formation within a formation would vanish into nothing in an instant.
"Spirit Stone consumption? I have some savings as well. It should be enough to hold out for a while."
"Besides, I have formation-related classics obtained from Heavenly Capital. Fellow Daoist Su, since you can set up a formation within a formation here, as long as your formations