Guliang Yuan had also spent six years inside the Void Pagoda, breaking through three consecutive realms to reach the Second Layer of Heavenly Immortal.
One of those realms was provided by the Innate Dao Fetus, while the remaining two were the result of natural breakthroughs.
After becoming an Immortal, cultivation time is calculated in centuries, and it is common to be stuck at a minor realm for tens of thousands of years.
Chapter 329