Zhou Qing was certain that even if his Blood Circulation System Martial Soul did not possess Innate Full Soul Power, it had come close.
However, before awakening his martial soul, he had cultivated the Mysterious Heaven Skill. The Internal Energy he cultivated in advance had been drawn away together with part of the martial soul's innate soul power during the final test of his Innate Soul Power.
This meant that another portion of Innate Soul Power still remained within his martial soul.
Before obtaining a spirit ring, soul power could reach only level ten at most. Even if there were additional soul power, it could not raise his level.
As for the theory that "after reaching a bottleneck, one can continue cultivating without obtaining a spirit ring, and the results of that cultivation will manifest once a spirit ring is acquired later," Zhou Qing felt there was a problem with it.
Both Tang San and he himself had continued cultivating soul power after reaching their bottlenecks, yet their current increase in soul power was not due to those cultivation results. Rather, it came from the energy carried by their spirit rings and Soul Bones, as well as the Innate Soul Power still hidden within their martial souls.
In other words, after reaching a bottleneck, continuing to cultivate soul power without obtaining a spirit ring would, aside from improving one's precision in controlling soul power, provide no substantial help toward increasing soul power after a soul master later acquired a spirit ring.
So—
The cost-effectiveness was too low!
Because soul power that was not innately carried by the martial soul simply could not be retained.
What did innate mean?
Something one was born with!
Therefore, Yu Xiaogang's theory probably applied only to soul masters after they obtained their First Spirit Ring,