Cao Zhen had said when he imparted the Five-thunder Righteous Method to his disciples,
that according to the classification of spells, the Five-thunder Righteous Method is a Lower Grade Heaven Rank spell. However, before entering the True Immortal Realm, one cannot cultivate the Five-thunder Righteous Method to its peak, achieving the power of a Lower Grade Heaven Rank.
Now, both he and his disciples have long entered the True Immortal Realm, and his disciples have been cultivating the Five-thunder Righteous Method consistently. No matter whether it is the Fire Thunder Orthodox Method or the Gold Thunder Orthodox Method or the Water Thunder Sect, they have all cultivated to the power of a Lower Grade Heavenly Tribulation.
In truth, there was one thing he didn't mention at that time, though his disciples should have felt it later.
Which is that the purest form of the Five-thunder Righteous Method can actually reach the power of a Mid Grade Heaven Rank.
