In This Life, The Greatest Star In The Universe - Chapter 38:

Dao Fa leads to spirits, and medical therapy leads to ghosts.

A third-rate university graduate who was supposed to run around in a mess for his livelihood, but because of an inadvertent shot to save people, whether it is extremely peaceful and rewarding for his good people, he has obtained the legendary inheritance of the mysterious arts and medical methods of the experts in the realm of self-cultivation. Another brand new and weird new world!

- Description from novelbuddy

Born to a mother on death row and subsequently raised in the prison, Gu Tianyou did not have what most people would consider a ‘normal’ childhood. Instead of the usual math and history one might learn at a public school, he had criminals for tutors. He received regular lessons from notorious serial killer, Dr. Miao, and earned protection from the respected Master Long.

With such a unique background, Gu Tianyou graduated from the Police Academy with little difficulty, and was assigned as an undercover cop. But will the skills he learned from a lifetime of being cared for by criminals be enough to help him take criminals down?

In the foreign world, the martial artists dominate the world and the sword of the emperor controls the fate of hundreds of millions of lives! Long Yu, the number one killer on Earth, after dying, takes rebirth in this new world in an aristocratic family of martial artists but faces rejection because he is unable to practice martial arts.

- Description from Novelupdates