The moment Zhong Yue entered the upper lightning zone, and the 36 Pan Aos and Kui Long lunged into the sky, attempting to stop him down. They all rose higher and higher into the sky as the lightning started increasingly dense.
The stronger the cultivator, the more dangerous the lightning would be to them.
The lightning of heaven and earth was of the Pure Yang attribute while souls were aligned with Yin. Powerful lightning was capable of destroying cultivator souls into nothingness; so long as souls hadn't cultivated up to the Pure Yang stage, death would be inevitable.
However, cultivating the soul into the Pure Yang state was precisely the first step to becoming a deity.
With that being said, any other existence besides the gods themselves would have their souls be crushed away by the lightning.