No Hero - Volume 7, The First Step Toward the End: Sin, the Original

The protagonist of the collapse of the three former civilizations is Dr. Mei. What is the end of logic, the strongest brain, super intelligence, this is the story of the strongest scientist of Honkai with knowledge of the moon becoming the god of science!

- Description from novelbuddy

Kim Jeongjin, an editor of a publishing company on the brink of closing due to bankruptcy, ends up transmigrating inside a fantasy novel as the incompetent youngest son of a wealthy family.

And here he thought that he should live a rich life in this life…

“Why was I given a high-level skill? Don’t even bother!”

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…

Li Xiao Yao left S.W.A.T to become an ordinary security guard. While working, he happened to enter the VIP room and found Lin Wang Er still in the middle of changing. As revenge, she took him on a ride and kicked him out of the car.

After hours of walking, Li Xiao Yao finally managed to get back home just to be kicked out of the house. He then got an offer from his previous supervisor to become the bodyguard of the Tian Xi group CEO’s daughter both in game and in reality. But unknown to Li Xiao Yao the girl was actually…

- Description from Novelupdates