MTL - Evolved From Polluting the World - Chapter 136 tower at the end

Sue Kirin was a loser. Thirty years old with no hope for advancement at his job and no redeeming features except one, Magic. For as long as he could remember Kirin had dedicated his life to practicing the Arcane. Unfortunately, when he was passing down his knowledge to his niece, she lost control of her power resulting in a backlash of vicious energy that resulted in her being sent to the hospital, her life in critical danger.

C-class mercenary. Started as a No Class, possessing nothing.

13 years of survival in the depths of the ditches.

I’ve managed to return to the beginning, but…

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