If the barrier isn't attacked for a period, it will start to restore by itself, and the speed is quite fast.
Previously, Tian Chu Zhenren thought Ye Tianfan would use spiritual power to wear down the barrier because while Ye Tianfan slowly wore it down, he was already recovering his spiritual power. And once he was about to run out, he would use just a bit of spiritual power to wear it down further. This method would prevent the barrier from recovering and allow himself to quickly recover.
However, if a magical treasure is used for breaking, once you run out of spiritual power, the barrier will also start restoring quickly, even faster than Ye Tianfan could recover his spiritual power.
Of course, there's another method, which is for Ye Tianfan to break through to the fifth level of Qian Yuan. This way, he could directly break through the barrier using all his spiritual power.
