Apocalypse: God-level Zombie Synthesis System - Chapter 6

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Fang Ze transmigrated to a world filled with superpowers and became a police. Initially, he planned to carry out his duties diligently. However, by chance, he discovered that his true identity was actually a criminal who had been arrested. The police faked his identity and made him believe that he was one of them. Then, they utilized his remaining memories to solve the case and identify his accomplices. They had set up a huge operation and were ready to capture him and his accomplices at any time! Fortunately, he acquired a superpower called the Midnight Investigation Room. At midnight every day, he could conduct an investigation on a chosen target. During his investigation, not only could he hear the actual thoughts running through the head of his subject, he could also acquire different items based on the value of the information he collected. Some of the items he acquired included: a mushroom that could sustain its host’s beauty forever; a credit card that allowed its users to loan from the future unlimitedly; a loyal assassin troop that lurked in the shadow; a demon eye that allowed its user to pry into the other world; a kobold that could learn and train with double efficiency on behalf of its master; seeds that could be attached to enemies’ bodies to make them puppets; and tapes that could transform human bodies into rocks when applied. In order to resolve his crisis, he collected information and investigated the case while improving his ability and expanding his influence. Unfortunately, he uncovered an even bigger scheme after solving his case. This entire world turned out to be a scheme! Many years later, Fang Ze sat on the throne of the King of Darkness. Accumulated beneath his throne were the countless skulls of his enemies.

The youngest princess of the country of Stellaus, Marietta, was betrothed in a political marriage to the General of the great militant country, Oltaire. General Belvant was often said to be strong, a fierce and terrifying god of a warrior. On the other hand, Marietta was a delicate flower of a princess. Everyone felt pity for poor Marietta’s situation, however, the truth was that Marietta found the General very dreamy… The story of a 30-year old General with a scary face (who was actually quite nice), and the tiny and adorable 18-year old Princess in their times of conflict and of lovey-doveyness.