The Legend of Demon Body Cultivation to Immortality

[Qi refining and foundation building system, martial arts cultivation, no system, genius protagonist, cool writing, funny, smart] This is the story of a mortal swordsman entering the world of immortality. The protagonist has a special physique, a "humanoid demon body", which has no spiritual roots at all. He cannot refine his Qi or body. He has to borrow his cultivation from others, but he relies on his genius understanding of Taoism and martial arts to make a name for himself.