Wan E Bu She

The legendary assassin Wu Qi was killed when he made a careless mistake, and he didn't even know who killed him. That was when an entity called the Murderous Intent System appeared before him, promising to revive Wu Qi and tell him the truth behind his death, if he completed the missions entrusted to him. So Wu Qi will travel through time and space with the help of the System to stop people consumed by murderous intent. Even if he himself was beyond redemption, he will still try to save the people in each world.

(Source: Bilibili, translated)