Creation Formation Immortal and the others had only completed eight refinements in the Earth Immortal Realm. Without a world-shaking fortuitous encounter, their future limit would be Eight Dao True Immortal.
Compared to Nine Dao True Immortals, they were already far behind at the starting line.
Once all the Dao were opened, the Heavenly Dao River Tributary could still be gradually widened.
But no matter how much it was widened, there would only be eight Dao. A ninth Dao could never be added.
If every Dao was widened by one foot, a Nine Dao True Immortal's Heavenly Dao River Tributary would widen by a total of nine feet.
An Eight Dao True Immortal's Heavenly Dao River Tributary could only widen by eight feet.
After all the Dao were opened, their rate of growth would forever lag behind that of a Nine Dao True Immortal.
With one additional Dao, spending roughly the same price would always yield over ten percent more strength than others.
Over time, the gap would grow vast.
To catch up to a Nine Dao True Immortal, each Dao would need to be widened by more than one foot and one inch.
But once each Dao had been opened to a width of one hundred feet, widening it by even the slightest amount required an ocean of time, effort, and resources.
Compared to widening each Dao by one foot, widening it by one foot and one inch more would not merely cost ten percent more. It might cost several times, or even dozens of times, as much.
Those Dao that did not correspond to the tempering of the immortal body were collectively called miscellaneous Dao.
All of those Dao were crammed into the one river channel, one hundred feet wide, that appeared upon first breaking through to the True