The First Cultivator - Changing Existence - Chapter 12: The 2nd Floor -

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

Transmigrated to become a disciple of the demon sect, relying on the technique modifier to become a giant of the demon path.

[Detected the technique “Blood Nerve”, relying on devouring blood to cultivate]

[Side effect: easily affected by the spirit contained in the blood, becoming bloodthirsty, murderous, insane, and even brain dead]

[Please wait, system modification is in progress…]

[Ding! Modification completed and side effects canceled]

Ryoma Kogure, a high school student, is surprised when his childhood friend and best friend, Hirasawa Reo, who has always been popular yet indifferent to romance, suddenly confides in him about a love matter.However, when Ryouma learns that Reo’s crush is their quiet classmate, Otsuki Shizuku, he decides to help him out.While personally gathering information on Shizuku for his best friend, Ryoma is unexpectedly summoned by the school’s most beautiful girl, Asahina Alisa!She, being Shizuku’s best friend, mistakenly believes that Ryouma has feelings for Shizuku…!?Caught in Alisa’s misunderstanding, Ryoma scrambles to sort things out…As they began supporting their best friends for their own reason, Ryoma and Alisa grow closer——A romantic comedy that starts with friends supporting each other’s love!

Xiao Ran transmigrated to a fantasy world. As a dungeon guard in the Celestial Dungeon, with a special floor called the Purgatory meant for powerful demons and martial arts experts, he faced a huge challenge from the start. The Eldest Princess acquired a forbidden martial arts technique and was banished to the Purgatory. However, no one was powerful enough to restrain her. All the dungeon guards were defeated. Xiao Ran stepped up and declared, “Your Highness, it’s better for you to behave yourself on my territory” and effortlessly subdued the Eldest Princess.

He progressed from imprisoning the Eldest Princess to delivering the Great Xia Kingdom from the evil clutches of various demons and evil martial arts experts.

…

Xiao Ran was the mastermind behind the scenes.