The Regressor Only Protects Me

Humanity was designated as a disruptive species of the Cosmic Ecosystem. To reduce humanity's numbers, the universe's administrators initiate a survival game. Jin Jaehee, having returned from the final stage of the game, reaches one clear conclusion: "Kang Shion, only he can lead us to victory in this game."

Kang Shion, a genius with an unparalleled mind. Jin Jaehee, a regressor who lost in the survival game and returned to the past. With the regressor as his ally, Kang Shion begins to unravel the death game with unprecedented skill.

(Source: Naver, translated)