Common Sense of a Duke’s Daughter - Chapter 7

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

While reading a book, a sparkle of light disappeared. And, as it did, a message appeared.

Step inside if you dare, but be warned—this is no ordinary shop. Those who enter never leave the same… if they leave at all. A sinister force lurks within, fueled by a dark past and a thirst for revenge. The price? Twelve lives for twelve sins. As officials race to put an end to the bloodshed, the shop’s deadly grip tightens, claiming innocent victims one by one. Will anyone uncover the truth before it's too late? If you crave spine-tingling horror, heart-pounding thrills, and a mystery that refuses to stay buried, this book will haunt you long after the last page.

Freshly turned eighteen, John Newman, a helpless nerd, suddenly gets video game abilities granted to him. A mysterious higher power, a secret Abyss of magic beneath the surface of the normal world, mages, martial artists, eroticism, tragedy and a harem of hot girls awaits.