The First Cultivator - Changing Existence - Chapter 787: Skymerge -

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

On earth, Felix is just a normal guy, a bit of a loner but otherwise normal. In the multiverse, under the rule of The System, he's a caster. Fascinated by magic and hungry to learn, grow and discover, this series follows Felix on his adventures through the integration and beyond.

[Harem + Light System + Mystery + Eerie world]After being transported to an unknown realm, Huang Ye unexpectedly obtained a martial arts manual—the Jade Maiden Heart Sutra, a technique meant for women.With no other choice, he followed the concept of opposing yin and yang, practicing the technique in reverse.By accident, he mastered a form of Dual Cultivation. From then on…