Fang Yi's Inner Strength was actually at the second level of the Earth Level, which was divided into six stages within the Earth Level hierarchy.
Each Martial Artist at a particular stage could use their Inner Strength ingeniously and had also unlocked their Dantian.
Martial Artists at the Earth Level not only possessed Inner Strength but also stored Inner Strength within their Dantian. Thus, in terms of power, Martial Artists at the Earth Level could be said to completely overwhelm those at the Human Level.
If Fang Yi hadn't been at the ninth layer of the Human Level, and had not half-stepped into the Earth Level, coupled with his robust body, he would probably have been lying on the ground spitting blood by now.
Therefore, in Bai Qifeng's eyes, he merely thought Fang Yi was a joke.