Thumbs Up, Level Up - Chapter 300

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Humanity has been gradually transported to the Abyss by a bored god to compete against other races and monsters.The problem is… humanity failed. In a last desperate push the strongest survivors chose a comrade to travel as far as possible back in time.

Reborn into a fantasy world of magic and aura, Rowan is the second son of a ranch family living boringly in a backwater village, with no magic and no inheritance.To avoid rotting away in the countryside, he becomes a mercenary instead. Better to die fighting than waste away.After his first kill, the Black Dream awakens: a power that lets him plunder abilities from everything he defeats.But it's more than that. When he fights alongside others, their techniques become his: a master archer's deadly precision, a hunter's supernatural tracking, an assassin's shadow-step…Every ally becomes his arsenal.Ascension awaits! From the lowly dirt to the throne of the gods.

Harem Dynast is the story of a princess set up in a political marriage with King Lorent, a great conqueror who is often mentioned in the Harem novels.