Generally speaking, ghostly creatures of the Netherworld Clan, when confronted with such intense sunlight attribute light, are utterly averse to it.
Thus, the extreme yang formation, as a forbidding array of utmost firmness and yang, naturally has a considerable restraining effect on the Netherworld Clan.
No wonder Taoist Friend Yin seems so astonished.
"Many thanks to Brother Yin for the warning; this formation is indeed extraordinary. I barely touched it and it has already peeled off several layers of skin," Liu Ming laughed it off, while simultaneously retracting his arm, on which the skin, slightly charred, started to heal rapidly amidst a wrapping of black mist, visible to the naked eye.
"We mustn't linger here any longer; it's crucial to pass through this wasteland as quickly as possible. Fortunately, the dispersal of the ten suns leaves plenty of gaps," after reminding this, Taoist Friend Yin took out a blue-glowing sphere from within his clothes and gently squeezed it.