The heavenly tribulation had only just begun and was still sparse, a patch here, a clump there. Their attributes differed as well: some were purple firmament thunder, some green firmament thunder, some Wind-Fire Thunder, and some Heavenly Astral Thunder.
Gradually, more and more thunderclouds were drawn in. According to their differing attributes, they attracted and repelled one another, producing all manner of wondrous interactions of generation and restraint as they gathered into separate clusters.
Small patches joined into vast masses, covering an ever greater area. Once tribulation clouds of different attributes merged, they underwent unexpected changes, giving rise to even more formidable heavenly thunder.
Everyone's circumstances differed, as did the timing and strength of the heavenly thunder they drew down. Some thunder came first, some later, arriving one wave after another until the tribulation clouds had amassed into an enormous expanse.
This heavenly tribulation would last three years, coming and going, sometimes strong and sometimes weak. Thunder tribulations and fire tribulations still predominated, with demon tribulations interspersed among them.
The demon tribulations were the most dangerous. Each person's depth and strength of cultivation differed, so the thunder and fire tribulations they summoned differed, as did the demons they attracted. Heavenly demons followed the heavenly thunder and heavenly fire down, directly assailing the primordial spirits of those undergoing the tribulation. Some even fused with thunder and fire to form demon thunder, attacking their physical bodies and stirring their blood and vital energies, making them suffer unbearably from head to toe.
Some yin demons slipped silently into people's hearts, making them see all manner of illusions—for instance, that the heavenly tribulation had already passed—or even sending them charging furiously at the tribulation clouds above...
Such things were too numerous to list.
Only when the heavenly tribulation was at its strongest did Shi