Three hundred years after a global catastrophe mutated Earth's wildlife into unstoppable fierce beasts, humanity clings to survival within fortified base cities. In this dangerous new era, Beastmasters who can contract and command these monsters are the only line of defense. Su Yang, a transmigrator from modern Earth, awakens during the critical coming-of-age ceremony with a mysterious System that no one else can see.

While others rely on flawed appraisals to select low-potential pets, Su Yang's cheat ability reveals the hidden truths of beast eggs, exposing their true talents and growth ceilings. Rejecting the safe choice of a common Bronze-grade wolf, he gambles on an unidentified egg, securing a Storm Eagle endowed with a mythical-grade talent that instantly elevates its potential to the Monarch realm. Now armed with an overpowered companion and the knowledge to identify countless legendary beasts hidden in plain sight, Su Yang begins his ascent from a commoner to the world's supreme Beastmaster, ready to turn the tide against the apocalyptic horde.