I Can't Cultivate In Cultivation World

David a normal ugly middle aged person bought in world where humanity constantly harassed by otherworlds and greedy humans. David got a weird shop where he can buy anything with money. He swears he will tear down heaven and eat dragon. David- shop exchange 1 cultivation technique Shop- "Adamantine Bone Refining Technique", 100 million gold coin. David- ...... (Vomiting blood) Hello This is my first novel please comment on mistakes. -18+, Married Protagonists, Comedy, Cunning Mc, Logical Story.