Overlord (WN) - Volume 2 Chapter 23

Through a mysterious portal, Chen Jin arrived at this strange place – a post-apocalyptic world where civilization had been destroyed.

Consequently, he found –

A piece of metal scrap
A robot trash collector
A battleground
A city
A ton and more of gold
A copy of high-tech documents
A…
In short, Chen Jin found a planet.

- Description from Novelupdates

Inside the 3000m underwater station, an international group of scientists and engineers live and research for possible settlement of entire human race. Park Mu-hyun, a reserved dentist joins the station in hopes for a quaint life in the deep sea. However, things quickly go south when the station gets attacked by a mysterious group of people.As the water starts to fill in the living quarters, Park Mu-hyun grabs his backpack and immediately runs for his life, but where to? Now, the peaceful station becomes the ultimate survival stage of cult madness and chaos.

The Celestial Express is a train that goes from one galaxy to the next, picking up passengers along the way.Its Navigator, the one who drives it through the stars, is a god who can grant those passengers wishes.Jax arrives on the Celestial Express with no memories but a single wish—to save someone. After learning what the Navigator is capable of, he decides to go find him.To find the Navigator, he must go through TEN different Carriages, all of which contain a world of their own.And, he must do it with a restriction called Single Spell Sorcerer.

Ronnie, a college student with a boring life has everything around him change when his whole world is turned upside down by a woman he accidentally summons while trying to summon a magical familiar as a game.His peaceful and tranquil days are disrupted as he tries to help her fit into human society while also searching for a way to break their bond.Hell further breaks loose when he discovers that his familiar is indeed the demon queen and mysterious forces start trying to eliminate him for reasons unknown.He struggles to protect himself, adjusting to having a demon queen in his life, and understanding his growing feelings for her.