One could only imagine how difficult it was to cultivate in such a place. However, as long as one persisted, the benefits one could obtain would far exceed that of cultivating in the outside world.
It was far from just a small increase in cultivation. One's entire body would undergo a transformation. It was similar to cultivating with a weighted suit. The more difficult the cultivation, the stronger one would be.
However, this was true only for Chu Yuntian and Chu Xuelian. To Chu Yunfan, this was simply a sacred land for cultivation. This was because the other two did not dare to simply absorb the Fire Spirit Energy in the air. They were afraid of being burned. But to Chu Yunfan, this did not matter.