Yin-Yang Two Forms Sword Array

Holding the inscription pen, Zhang Ruochen continuously poured his Genuine Qi into it. His mind was empty as his Spiritual Power was completely immersed in the world of the sixth level array's inscription.

"BOOM!"

Loud rumbling sounds resounded from outside as the attacks raged on. The whole underground palace shook violently.

Han Qiu was standing nervously beside Zhang Ruochen. She did not dare to make a sound, afraid that she would interrupt him.

Almost two hours had passed before Zhang Ruochen finally put away his inscription pen. Only then he realized that he was soaking wet from sweat.

Zhang Ruochen heaved a long sigh of relief. He then retrieved Spiritual Crystals from the Spatial Ring one after another. He inserted these Spiritual Crystals into the small pits of the stone wall.

The pits on the wall was completely filled after being embedded with a total of 864 Spiritual Crystals.