But, Zetian, remember, only through rigorous cultivation and the comprehension of Xuanmen's true techniques, can you produce righteous thunder. Otherwise, relying on transformation techniques and the art of assimilation only results in the evil thunder of Zuodao, which will surely be dispelled by true techniques and will harm you. Therefore, between the righteous and evil paths, you must never favor one over the other. Keep this in mind."
"Yes, disciple understands."
Song Dayou said the words, "Without the ancestral master's permission, one must not privately teach thunder techniques." Yet, despite saying he wouldn't teach thunder techniques, in truth, he was teaching all about thunder techniques; while the skills themselves weren't yet taught, the genuine heart methods had already been imparted.