When Zhu Shiyu followed Chen Fei from Cangxia Domain to Cold Mountain Domain, he had only just broken through to the Mid Realm Lord stage.
Only a few years had passed since then. Zhu Shiyu had in fact only recently stabilized his Mid Realm Lord cultivation and was still a considerable distance away from using a top-grade Tenth Order Status Spiritual Material.
However, top-grade Tenth Order Status Spiritual Materials were not solely used to break through to the Late Realm Lord stage. Even before breaking through, they could be directly refined into one's body.
Because Status Spiritual Materials enhanced the Heavenly Status within one's body, even if one's realm was insufficient and the Heavenly Status could not truly be elevated, it would still indirectly strengthen the foundation of one's own Heavenly Status.
After one's foundation was strengthened, the most obvious change was that one's perception of heaven and earth would suddenly improve, much like a Late Realm Lord comprehending cultivation techniques that a Mid Realm Lord needed to cultivate.
With such a lofty vantage point, the speed of comprehending cultivation techniques would naturally increase at once.
In fact, many top factions in Cold Mountain Domain used this method to cultivate Realm Lords of exceptional talent or sufficiently deep backgrounds.
Back when the origin demon calamity had not yet erupted, many sects and factions even used Eleventh Order Status Spiritual Materials to nurture their own disciples.
However, using this method came with a minor drawback: one's Heavenly Status would reveal a trace of abnormality.
At such times, a cultivator of sufficiently high realm needed to use a secret art to suppress the abnormality in the Heavenly Status.
For Chen Fei, performing such a secret art on a Mid Realm Lord was naturally as easy as turning over his hand. In merely