Path To Multiple Great Daos

The typical time one would need to open up a text could possibly range from weeks or months. Cain only had a rough estimate, but with his experience, he knew he was close to being completely accurate. 

Lesser talented Martial cultivator's rate of comprehension would need to expand a significant amount of soul energy simply trying to understand a single energy principle.

Once they had filled that blank in, their soul energy would feel strain, forcing them to stop and recuperate. This leads to an arduous process of comprehending and then needing to take a profound amount of time to rest their souls.

Even Cain couldn't say his soul energy can recover near instantaneously. Other geniuses, such as Divine Decree Lords, would need hours, sometimes a day, depending on how drained their soul's cores are.

But of course, Cain didn't encounter regular problems other geniuses would have.