After he entered the Luo Yuan Daoist School, he gained an understanding of the subsequent levels of the Sword Dao Rhythm. Just comprehending the Dao Rhythm is considered Entering Dao, followed by Understanding Dao, Transformation, and Unity.
Entering Dao and Understanding Dao are the easiest to comprehend.
But the subsequent Transformation becomes difficult.
Generally speaking, Void Immortal Level can achieve Entering Dao.
Earth Immortal can achieve Understanding Dao.
However, to step into Heavenly Immortal, one must undergo Transformation.
This is precisely why Void Immortal and Earth Immortal are not hard, the challenge lies with the higher levels of Heavenly Immortal and Profound Immortal.
This is also the reason why those who achieve Heavenly Immortal, even if they are servant disciples, can gain immortal status.
The reason is simple; wanting to undergo Transformation is too difficult.
