MTL - The Devil’s Cage - Chapter 1789 missing one

Due to a mistake on his student’s part, a super Martial Artist had received a wrong class in an online game and had become a mage. He who was used to curbing violence with violence and using strength to subdue strength could only make the best out of his mistake. Taking on a new lease in life, he became a violent close combat mage. When strength and magic came perfectly together, a new gaming path had been opened by him!

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

Zhou Peng accidentally travels through time, finding himself in a weakened and sickly body with a shattered dantian, unable to cultivate qigong. Fortunately, the heavens show mercy by bestowing upon him an upgrade system.A waste? That's all in the past...Leveling up by slaying monsters, effortless and hassle-free, he no longer has to worry about cultivating.Killing monsters grants upgrades, and so does killing people. In the eyes of others, the awe-inspiring and prestigious sect masters are nothing but shining golden bosses in his sight...With the ability to upgrade, who am I afraid of? When so-called geniuses encounter roadblocks and fail to breakthrough, all I need to do is slay a few more beastly demons. Of course, sect heads, sect masters, realm lords... are even better.For the sake of my path to divinity, offer up your lives!

This is a very interesting thing. It is obviously dim and black, but it can emit a golden light, which makes people deeply fascinated by it…

- Description from novelbuddy