In a dystopian world dominated by the relentless threat of Catabolic Beasts, humanity's last hope lies with those who awaken unique abilities. Elite academies sprout throughout the land, grooming the next generation of warriors and leaders. However, not all abilities are deemed worthy, and not every individual is seen as an asset.

Zhang Ping's journey begins when he transmigrates into the body of a young, ambitious student. He dreams of waking up to a powerful ability that would place him among the legends of his generation. Fate, however, plays a cruel joke, bestowing upon him an ability ridiculed and dismissed by many as worthless.

But, as the adage goes, "One man's trash is another man's treasure." Zhang Ping's so-called "worthless" ability opens doors to a realm of secrets that cast shadows over his academy and town. Determined to rewrite his destiny, he takes the audacious step of swallowing the forbidden "stone of contract," forging an unbreakable bond with his own powers.

This bold act unravels the fabric of his reality. Zhang Ping finds himself amidst a barrage of superpowers, confronting mutated beasts, and navigating a perilous parallel world. As the lines between friend and foe blur, he realizes that his "useless" ability might just be the wildcard humanity desperately needs.

As Zhang Ping rises from an overlooked student to a beacon of hope, readers will be compelled to question: In a world of extraordinary abilities, what truly defines strength and worth?

C901 No Sin Door