Chu Feng's eyes burned and his eyelids would burn his hand when he touched them. He was too happy and excited because he seriously had been thinking about this Buddhist Race breathing technique for a very long time!
He had once experienced it for himself before and so was fully aware of its wonders. When the great sound of thunder rumbled out, all of the bones and inner organs in his body would shake altogether. Blood qi surged as it was purified while his entire body was being nourished and baptised. This had endless benefits for an evolver.
The Thunderous breathing technique was one of the earliest techniques Chu Feng had obtained. When lightning pounded his physical body and stimulated the potential of the human body, he experienced tremendous benefits.
Unfortunately, that was only an incomplete technique which only enabled him to practice it to the Shackled realm; it didn't have sections following up from that.