Slag Shou Cultivating Manual

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 — Description from novelcodex.org