Megami Buchigire - Chapter 32 - Isekai Onee Monogatari 5

Luo Yi, a high school dropout in his original world, was isekai’d into the world of the Witcher 3. Starting out as a weak boy named Roy in the village of Kaer, Lower Posada, he was determined to grow stronger, no matter what it took. The first step toward becoming a legend was to kill. And his first kill was… a rooster. ‘You gain 1 EXP.’ Of course, Roy had his own cheat system like all the other isekai protagonists. His first step to becoming a legend started now…

When the heavy curtains of night descended, darkness fell upon the earth. What will later be known as the dawn of the “Dark” era, humanity once again unfolded a new path of evolution. While retaining the memories of surviving ten years in the apocalyptic world, Ye Chen awakens back on the very day the disaster struck; all he can do is protect the people dear to him, and then….

With the might of an ant, set foot upon the pinnacle of this world!

The people lost in the thralls of everyday life, aimlessly struggling for survival in this world, move forward; there will surely be a path only you can open….

- Description from Novelupdates

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

He is the master of six kingdoms. As long as he wanted, his cavalry is ready to wipe off any country.