MTL - Wife is Not Divorced - Chapter 4

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates

When Fang Zheng opened his eyes, he was surprised to find himself reborn in a fantasy world of magic, dragons, knights, and princesses. Not only that, but even the game system that Fang Zheng had designed before also followed him into this world. Then, his next step would be to traverse thousands of plains, gain endless strength, become a brave hero, defeat the devil, marry the princess, reach the apex in life… wait, wait, wait, before all that, why was he reborn as someone who everyone called a cultist?