MTL - Lost Lovers - Chapter 21

After being reborn in the ancient times before the Great God-Conferment War, Li Changshou becomes a minor cultivator. He is neither destined for great things nor great woe. His only dream is to live a long life as a cultivator. In order to survive in the cruel Primordial Times, Li Changshou tries hard not to accumulate any karma—killing inevitably leads to feuds.

Thus, he always plans thoroughly before doing anything and never allows himself to walk into dangerous situations. He hides his trump cards well, trains himself in escape techniques, refines poisonous pills, and masters his mystical abilities. Before making any moves, he takes on an extremely steady demeanor. Yet, every move of his ends up earth-shattering. Once he is done, he will disappear without a trace.

Li Changshou originally plans to remain hidden and safe in the mountain. There, he is supposed to cultivate until he ascends to immortality. However, everything changed one year when his master seems to think that their lives are too peaceful… He takes in a junior sister…

She shouldn’t have got drunk, so she wouldn’t have court the troubles.
She slept with a handsome man and would be sent to the police?
Oh, my sweet Jesus…
“So you just ran away like nothing happened after you slept with me?”
“Old jerk! Even if I had the initiative, it was you who took advantage of me!”
As a saying goes, the more spoiled a president gets, the more likely he becomes a scumbag.
An adorable ‘wildcat’ vs. a scheming frenemy.
This was a love rivalry between a modern Cinderella and a Big Boss.
As time flew, the world was like a fleeting show.
When they met again after several years of separation, he held her hand tightly and swore that he would never give her any chance to leave him again!
Finally, he asked her to marry him and pampered his cute wifey with his endless love.

- Description from Novelupdates

I met the male lead in prison.

A person in their third year of high school, experiences the arrival of a divorce comeback system 20 years early. At 38 years old, with a failed marriage, standing at the crossroads of the established and confused years, you recall your young days with your childhood sweetheart. After marriage, you cut off contact and have no more news of her. Re-establishing contact with Xu Qianqian will reward you with 300 RMB. Eighteen-year-old Jiang Nian glanced at the system task on the panel and then at Xu Qianqian living next door, falling into deep thought. Hmm... it seems the system came early. There is another issue: who is the future ex-wife? Hmm... Jiang Nian couldn't hold back. Being eighteen every year, he foresees a divorce in the future. The system issues a task to take revenge on the future ex-wife. Jiang Nian looked at the un-darkened version of the future ex-wife in front of him and fell into thought again. The childhood sweetheart, future ex-wife, and future ex-girlfriend, all appear in their younger versions.