From Divine Transformation Late Stage to Hollow Void Realm, the prodigies of the Cangtian Realm typically step into the Hollow Void Realm within a time span of three to four thousand years of cultivation; any later and they would no longer be considered prodigies.
Regardless of the realm, the less life consumed, the more potential is retained, and this is also true for Hollow Void Experts.
However, Hong Rongduan also knew that the Mansion Master was deliberately giving Ji Yang a chance, allowing Ji Yang to step into the Hollow Void Realm within five hundred years. If Ji Yang failed to break through to the Hollow Void Realm when the time came, the Mansion Master would not hold it against him, but rather use this as a pretext to prevent other Elders from opposing.