Legend of the Evil God

Legend of the Evil God summary:

This story is about an Evil G.o.d whose motto in life is: “As long as it’s on sale, buy it!”
Hmm… that’s not right…
This story is about a 10 year-old (self-proclaimed) prodigy whose motto is: “As long as it’s on sale, buy it even if it’s useless!!!”
Hmmm… that’s not right either…
Anyway, this dude gets thrown into another world after an asteroid almost decimated the Earth.
With just two measly books on ‘secret cultivation arts’ that he acquired… (yup you got it. It was on sale), how will he survive in this strange new place?