Saving The Villainous Monster From The Male Lead - Chapter 10 - 9: The Proposal

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

I’ve possessed the mid-boss who tortures the protagonist and receives true education.Am I crazy? How dare I do such a thing to the person who is supposed to be the protagonist?I even planned to treat all the protagonist’s friends hospitably…“Everyone, wait for me! I will definitely become stronger and come to save you!”Oh. Running away.

The Apocalypse is in full swing. Defiled - powerful creatures corrupted by the Great Collision - prowled the lands in search of prey. Unfortunately for them, the human race had long since retreated behind the secure walls of the Sanctuary of Everlast. During one of his regular excursions outside the Sanctuary, Alden is separated from Celeste. - his childhood friend and crush. In that moment, he came to regret never summoning the courage to confess. Somehow managing to survive thanks to some trickery, Alden awakens as a mage. Instead of receiving a normal power, he gains the ability to decay. What’s more, during his ascension, he received a vision from his future self advising him not to trust the Asterons - celestial beings who had saved his race from inescapable doom. Normally... such a revelation wouldn’t faze Alden. However, there was only one major problem with the declaration, though. Celeste was bound with an Asteron. And not just any normal Asteron... She had made a pact with one of the Divine Sovereigns.

The male student, Fukai Nagamasa, ignores his studies for college entrance exams in favor of following the path to chuunibyou. As he fainted during night cramming session before the exams, he realized that he was transported to a parallel world as a feudal lord in the Sengoku Era. Not to mention that suddenly, he was marrying the sixth Demon King, Oda Nobunaga’s little sister, the one who was purported to be an unrivaled beauty?