According to that book, the energy of nature is called "Force of Heaven and Earth" and people and Fiend beasts with the talent can absorb and store the 'Flux ' in order to empower their bodies, prolong their lives and use Flux techniques. The "Flux" can be used as a mean to empower the body and the martial techniques or can be linked to someone's own Mental energy to release Force attacks. The 7 Force types are light, darkness, fire, water, earth, wind and thunder and someone's aptitude to one of these is decided at birth. Generally, everyone has the aptitude toward one Force yet the difference in mental energy decrees his ability to manipulate that element'
David was currently having a lesson in the classroom about philosophy but his mind was constantly wandering on the topics described in the old book.
For those of you thinking David will have to restart his entire cultivation; No he won't!!! He just needs a little time of practice and he would be back to his peak and it won't be slow at all. He needs to get his hands on a flux technique and integrate his entire techniques with it ... Regardless, the next ten chapters and above would be full of action.