Kissing Hellfire: Marry Me, Evil Lord - Chapter 10: The Engagement

One day, Su Qi suddenly discovers he has a peculiar ability: he can see Easter eggs hidden in the world around him.These aren’t just bits of extra information; by performing specific actions, he can unlock hidden rewards.While everyone else is fleeing in terror from a vengeful female ghost, Su Qi is already setting the table for a candlelit dinner, chatting amiably with her.[You acquire her husband's hat, a mysterious artifact that, when thrown, locks onto enemies and delivers a devastating mental shock.]When zombies overrun the streets, and survivors scramble for axes and kitchen knives, Su Qi confidently strides in, wielding a sound system in one hand and a heavy-duty machine gun in the other, casually clearing out the neighborhood.[No one can defeat me in my BGM.]This is the Abyss—the birthplace of despair and decay, where worlds crumble under fear and madness.This is also a paradise where countless seekers pursue the footsteps of gods.Myths of the past and epics of the future are written here in grand and tragic splendor.Until Su Qi shows up.With a mop soaked in the blood of a recently stunned god, Su Qi scrawls a few bold words onto the epic tale:“The Abyssal Garden: No Room for the Idle.”

800 years ago, 3000 dimensional gates opened across the entire world. In that moment, it was as if 3000 different colored eyes opened across the world as hordes of monsters swarmed out of these gates like tears.

Some could destroy city walls with one strike; They had bodies the size of a giant and fed on humans

Some latched onto humans, absorbing their bodies’ nutrients and enslaving humans

Some infiltrated the humans’ cities, disguising themselves as normal human beings while feeding upon human blood to sustain themselves.

In a night, the Human race fell to the bottom of the food chain.

The world had turned into a paradise for monsters…

- Description from Novelupdates

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

Luo Qing Chen is a wandering spirit that died thirty thousand years ago, roaming the Chaos Space

In order to not turn into dust, she is bound by an ice cold system to travel through time and space to complete missions.

Girls that pretend to be weak?  Slap them without explaining.

A silly cannon fodder?  Helping them amass treasures.

Meeting a real male god?  All of them will pamper.

System: Dear masters, what do I do if my host even dares bully the heavens?  Waiting for an answer, it’s urgent!

A certain male god: Change systems.

System: ヽ〔?Д?〕丿

- Description from Novelupdates