Being at the fourth level of Qi refining at the age of 25 is undoubtedly slow,
Generally speaking, to successfully reach the Foundation Establishment, one needs to reach the late stage of Qi cultivation by the age of 30,
People like Zhao Chengyu have high hopes, but others, even if Zhao Chengjing is 28 this year and has been stuck at the peak of the sixth layer of Qi refining for several years, her hope of reaching Foundation Establishment is rather slim.
At the age of 30, reaching the seventh stage of Qi refining generally requires one to reach the peak of Qi cultivation, which takes at least 20 years for the fast ones,
And if one still hasn't reached the level of Foundation Establishment past 60, then between the decline in Vitality and Blood, and the diminishing vigor, it becomes much harder to establish a foundation.