Vast and mighty spiritual power surged out from Gu Xi's body and instantly sank to the ground.
Immediately after, the earth shook and the mountains shook. Burning clouds rose up in all directions. The temperature suddenly rose, and the spiritual energy in the world became restless again.
A wave of destructive energy instantly occupied an area of dozens of miles!
At this moment, beads of sweat appeared on Gu Xi's forehead, and his face was slightly pale.
Although the System had refined the Heaven Slayer Karmic Fire Formation to a perfect state, and its power was comparable to a high-tier heaven-grade spirit array, it was indeed a little exhausting for him to use this array at full strength. Even with the Saint stage, he was still somewhat unable to bear it.
"Looks like I still have to raise my cultivation realm as soon as possible! Otherwise, it'll be troublesome to use these good things."
