Beginning with the Ubume Bird - Chapter 302 - 28 War Shadows

In a modern world where cultivators need a place to cultivate or vent their boredom, there are private businesses that set up instance dungeons with the aid of technology and cultivation magic to enable cultivators to train and commoners to experience the life of cultivation. They are called dungeon suppliers.
Xie Jin's one and only dream was to be a dungeon supplier and when his only relative passed away, the relative's inheritance gave him a plot of land and surprisingly, a 'System' Module which the relative had previously used.
With the help of the system, Xie Jin decided to pursue his dream of becoming the number one dungeon supplier.

I fell in love. Her name was Shirasaka Yukino. I could only look at her from a distance. However one day I heard that she already had a boyfriend. Even if I love her, I can’t have her. The devil sent me an invitation. I can make her mine!

She is the wife completely ignored by him, yet also the woman he most cherishes. Ultimately, she forces her husband to divorce her by taking on the identity of a lover!She steals vital information and, carrying this man's premium seed, successfully makes her getaway!Six years later, father and son have their first online confrontation. The little bean successfully infiltrates the man's system and sighs at her, “Mom, this person is so dumb. Is he really my dad?”Mu Yiliang pats her son's head and says reassuringly, “He was so terribly fooled by me back then, which shows his IQ is very low. Luckily, you inherited mine!”Unbeknownst to them, the man on the other end of the computer has already listened to the conversation between mother and son. He sneers coldly, “Very low IQ? Mu Yiliang, let's see where you're going to run this time!”

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.