After Using Cheats, I Became The Strongest Beast Tamer - Chapter 19 - Monthly Test (Part 3)

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

After transcending to a new world, Ye Xuan miraculously obtained the Swallowing System.

He was once the most feared villain in the empire, a master of manipulation who wove chaos from the shadows. Ruthless, untouchable—until the day he was betrayed and executed by the very man he sought to control.But death is not the end.He awakens in the body of Lady Elara Valcrest, a fragile noble girl doomed to be a pawn in political games. Stripped of her former power, she is forced into an arranged marriage with none other than Cairon Everhart—the man who once killed her. He does not recognize her, but she knows him. And she will never forget.To survive, Elara must play a new game. One where deception is her only weapon, and trust is a dangerous illusion. She must outmaneuver her enemies, uncover the truth behind her execution, and reclaim the power she lost. But as she navigates the treacherous world of court intrigue, one question lingers—Was Cairon truly her greatest enemy? Or had she been blind to an even greater threat?Time is running out. The villain has been given one last chance. And this time, she refuses to lose.

Seo Tae Hyuk, jailed after being falsely accused.