Apocalypse System: The Last Administrator

When the sky shatters and Earth is chosen to participate in the Universal Survival Game, humanity is forced into a brutal apocalypse where monsters roam the world and every survivor awakens a mysterious System. Warriors, Mages, Assassins, Summoners, and countless other classes emerge overnight, giving humanity a chance to fight back. Everyone receives a class... Except Liam Carter. Rejected by the System and erased from its records, Liam becomes an anomaly—a human who cannot level up, learn skills, or even be recognized by the world's rules. Hunted by monsters and abandoned by society, he struggles to survive using only his intelligence, determination, and instinct. After surviving the impossible for seventy-two hours without the System, Liam unlocks the forbidden Administrator Authority, a power that allows him to rewrite the very laws of the System itself. Instead of learning skills, he can create them. Instead of following the rules, he can change them. But his awakening triggers an ancient alarm across the universe. For billions of years, the mysterious Celestial Overseers have used the Universal Survival Game to control countless worlds. Every civilization has fallen before them, and every Administrator has been hunted to extinction. Now, the final Administrator has appeared on Earth. As monsters evolve, kingdoms rise from the ruins of civilization, and powerful Awakened fight for domination, Liam must uncover the truth behind the System, gather allies willing to stand against the impossible, and challenge the gods who created the apocalypse. To save humanity, he must do more than survive. He must rewrite fate itself. — Description from novelcodex.org