The Mad Immortal: Starting by Refining the Cultivation of All Things!

(Yes, it's a System novel, but you can read it with your brain switched on. It's satisfying and the protagonist is invincible, but the story builds up gradually and holds together logically...) He transmigrates into the body of the founder of a small cultivation sect, only to find his cultivation at the third level of Qi Refining!

Just then, the founder of a rival sect launches an attack.

At this critical moment, he awakens the Cultivation Refinement System!

[A cultivator in the early Foundation Establishment stage can yield thirty years of spiritual energy cultivation...]

[A cultivator in the early Golden Core stage can yield one hundred and fifty years of spiritual energy cultivation...]

[A Nascent Soul cultivator can yield...]

(Who says System novels can't be hot-blooded?)